Source code for pycodestyle

#!/usr/bin/env python
# pycodestyle.py - Check Python source code formatting, according to PEP 8
#
# Copyright (C) 2006-2009 Johann C. Rocholl <johann@rocholl.net>
# Copyright (C) 2009-2014 Florent Xicluna <florent.xicluna@gmail.com>
# Copyright (C) 2014-2016 Ian Lee <ianlee1521@gmail.com>
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

r"""
Check Python source code formatting, according to PEP 8.

For usage and a list of options, try this:
$ python pycodestyle.py -h

This program and its regression test suite live here:
https://github.com/pycqa/pycodestyle

Groups of errors and warnings:
E errors
W warnings
100 indentation
200 whitespace
300 blank lines
400 imports
500 line length
600 deprecation
700 statements
900 syntax error
"""
from __future__ import with_statement

import inspect
import keyword
import os
import re
import sys
import time
import tokenize
import warnings
import bisect

try:
    from functools import lru_cache
except ImportError:
    def lru_cache(maxsize=128):  # noqa as it's a fake implementation.
        """Does not really need a real a lru_cache, it's just optimization, so
        let's just do nothing here. Python 3.2+ will just get better
        performances, time to upgrade?
        """
        return lambda function: function

from fnmatch import fnmatch
from optparse import OptionParser

try:
    from configparser import RawConfigParser
    from io import TextIOWrapper
except ImportError:
    from ConfigParser import RawConfigParser

__version__ = '2.3.1'

DEFAULT_EXCLUDE = '.svn,CVS,.bzr,.hg,.git,__pycache__,.tox'
DEFAULT_IGNORE = 'E121,E123,E126,E226,E24,E704,W503'
try:
    if sys.platform == 'win32':
        USER_CONFIG = os.path.expanduser(r'~\.pycodestyle')
    else:
        USER_CONFIG = os.path.join(
            os.getenv('XDG_CONFIG_HOME') or os.path.expanduser('~/.config'),
            'pycodestyle'
        )
except ImportError:
    USER_CONFIG = None

PROJECT_CONFIG = ('setup.cfg', 'tox.ini')
TESTSUITE_PATH = os.path.join(os.path.dirname(__file__), 'testsuite')
MAX_LINE_LENGTH = 79
REPORT_FORMAT = {
    'default': '%(path)s:%(row)d:%(col)d: %(code)s %(text)s',
    'pylint': '%(path)s:%(row)d: [%(code)s] %(text)s',
}

PyCF_ONLY_AST = 1024
SINGLETONS = frozenset(['False', 'None', 'True'])
KEYWORDS = frozenset(keyword.kwlist + ['print']) - SINGLETONS
UNARY_OPERATORS = frozenset(['>>', '**', '*', '+', '-'])
ARITHMETIC_OP = frozenset(['**', '*', '/', '//', '+', '-'])
WS_OPTIONAL_OPERATORS = ARITHMETIC_OP.union(['^', '&', '|', '<<', '>>', '%'])
WS_NEEDED_OPERATORS = frozenset([
    '**=', '*=', '/=', '//=', '+=', '-=', '!=', '<>', '<', '>',
    '%=', '^=', '&=', '|=', '==', '<=', '>=', '<<=', '>>=', '='])
WHITESPACE = frozenset(' \t')
NEWLINE = frozenset([tokenize.NL, tokenize.NEWLINE])
SKIP_TOKENS = NEWLINE.union([tokenize.INDENT, tokenize.DEDENT])
# ERRORTOKEN is triggered by backticks in Python 3
SKIP_COMMENTS = SKIP_TOKENS.union([tokenize.COMMENT, tokenize.ERRORTOKEN])
BENCHMARK_KEYS = ['directories', 'files', 'logical lines', 'physical lines']

INDENT_REGEX = re.compile(r'([ \t]*)')
RAISE_COMMA_REGEX = re.compile(r'raise\s+\w+\s*,')
RERAISE_COMMA_REGEX = re.compile(r'raise\s+\w+\s*,.*,\s*\w+\s*$')
ERRORCODE_REGEX = re.compile(r'\b[A-Z]\d{3}\b')
DOCSTRING_REGEX = re.compile(r'u?r?["\']')
EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[[({] | []}),;:]')
WHITESPACE_AFTER_COMMA_REGEX = re.compile(r'[,;:]\s*(?:  |\t)')
COMPARE_SINGLETON_REGEX = re.compile(r'(\bNone|\bFalse|\bTrue)?\s*([=!]=)'
                                     r'\s*(?(1)|(None|False|True))\b')
COMPARE_NEGATIVE_REGEX = re.compile(r'\b(not)\s+[^][)(}{ ]+\s+(in|is)\s')
COMPARE_TYPE_REGEX = re.compile(r'(?:[=!]=|is(?:\s+not)?)\s*type(?:s.\w+Type'
                                r'|\s*\(\s*([^)]*[^ )])\s*\))')
KEYWORD_REGEX = re.compile(r'(\s*)\b(?:%s)\b(\s*)' % r'|'.join(KEYWORDS))
OPERATOR_REGEX = re.compile(r'(?:[^,\s])(\s*)(?:[-+*/|!<=>%&^]+)(\s*)')
LAMBDA_REGEX = re.compile(r'\blambda\b')
HUNK_REGEX = re.compile(r'^@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@.*$')
STARTSWITH_DEF_REGEX = re.compile(r'^(async\s+def|def)\b')
STARTSWITH_TOP_LEVEL_REGEX = re.compile(r'^(async\s+def\s+|def\s+|class\s+|@)')
STARTSWITH_INDENT_STATEMENT_REGEX = re.compile(
    r'^\s*({0})\b'.format('|'.join(s.replace(' ', r'\s+') for s in (
        'def', 'async def',
        'for', 'async for',
        'if', 'elif', 'else',
        'try', 'except', 'finally',
        'with', 'async with',
        'class',
        'while',
    )))
)
DUNDER_REGEX = re.compile(r'^__([^\s]+)__ = ')

# Work around Python < 2.6 behaviour, which does not generate NL after
# a comment which is on a line by itself.
COMMENT_WITH_NL = tokenize.generate_tokens(['#\n'].pop).send(None)[1] == '#\n'


_checks = {'physical_line': {}, 'logical_line': {}, 'tree': {}}


def _get_parameters(function):
    if sys.version_info >= (3, 3):
        return [parameter.name
                for parameter
                in inspect.signature(function).parameters.values()
                if parameter.kind == parameter.POSITIONAL_OR_KEYWORD]
    else:
        return inspect.getargspec(function)[0]


[docs]def register_check(check, codes=None): """Register a new check object.""" def _add_check(check, kind, codes, args): if check in _checks[kind]: _checks[kind][check][0].extend(codes or []) else: _checks[kind][check] = (codes or [''], args) if inspect.isfunction(check): args = _get_parameters(check) if args and args[0] in ('physical_line', 'logical_line'): if codes is None: codes = ERRORCODE_REGEX.findall(check.__doc__ or '') _add_check(check, args[0], codes, args) elif inspect.isclass(check): if _get_parameters(check.__init__)[:2] == ['self', 'tree']: _add_check(check, 'tree', codes, None) return check
############################################################################## # Plugins (check functions) for physical lines ############################################################################## @register_check def tabs_or_spaces(physical_line, indent_char): r"""Never mix tabs and spaces. The most popular way of indenting Python is with spaces only. The second-most popular way is with tabs only. Code indented with a mixture of tabs and spaces should be converted to using spaces exclusively. When invoking the Python command line interpreter with the -t option, it issues warnings about code that illegally mixes tabs and spaces. When using -tt these warnings become errors. These options are highly recommended! Okay: if a == 0:\n a = 1\n b = 1 E101: if a == 0:\n a = 1\n\tb = 1 """ indent = INDENT_REGEX.match(physical_line).group(1) for offset, char in enumerate(indent): if char != indent_char: return offset, "E101 indentation contains mixed spaces and tabs" @register_check def tabs_obsolete(physical_line): r"""For new projects, spaces-only are strongly recommended over tabs. Okay: if True:\n return W191: if True:\n\treturn """ indent = INDENT_REGEX.match(physical_line).group(1) if '\t' in indent: return indent.index('\t'), "W191 indentation contains tabs" @register_check def trailing_whitespace(physical_line): r"""Trailing whitespace is superfluous. The warning returned varies on whether the line itself is blank, for easier filtering for those who want to indent their blank lines. Okay: spam(1)\n# W291: spam(1) \n# W293: class Foo(object):\n \n bang = 12 """ physical_line = physical_line.rstrip('\n') # chr(10), newline physical_line = physical_line.rstrip('\r') # chr(13), carriage return physical_line = physical_line.rstrip('\x0c') # chr(12), form feed, ^L stripped = physical_line.rstrip(' \t\v') if physical_line != stripped: if stripped: return len(stripped), "W291 trailing whitespace" else: return 0, "W293 blank line contains whitespace" @register_check def trailing_blank_lines(physical_line, lines, line_number, total_lines): r"""Trailing blank lines are superfluous. Okay: spam(1) W391: spam(1)\n However the last line should end with a new line (warning W292). """ if line_number == total_lines: stripped_last_line = physical_line.rstrip() if not stripped_last_line: return 0, "W391 blank line at end of file" if stripped_last_line == physical_line: return len(physical_line), "W292 no newline at end of file" @register_check def maximum_line_length(physical_line, max_line_length, multiline, noqa): r"""Limit all lines to a maximum of 79 characters. There are still many devices around that are limited to 80 character lines; plus, limiting windows to 80 characters makes it possible to have several windows side-by-side. The default wrapping on such devices looks ugly. Therefore, please limit all lines to a maximum of 79 characters. For flowing long blocks of text (docstrings or comments), limiting the length to 72 characters is recommended. Reports error E501. """ line = physical_line.rstrip() length = len(line) if length > max_line_length and not noqa: # Special case for long URLs in multi-line docstrings or comments, # but still report the error when the 72 first chars are whitespaces. chunks = line.split() if ((len(chunks) == 1 and multiline) or (len(chunks) == 2 and chunks[0] == '#')) and \ len(line) - len(chunks[-1]) < max_line_length - 7: return if hasattr(line, 'decode'): # Python 2 # The line could contain multi-byte characters try: length = len(line.decode('utf-8')) except UnicodeError: pass if length > max_line_length: return (max_line_length, "E501 line too long " "(%d > %d characters)" % (length, max_line_length)) ############################################################################## # Plugins (check functions) for logical lines ############################################################################## @register_check def blank_lines(logical_line, blank_lines, indent_level, line_number, blank_before, previous_logical, previous_unindented_logical_line, previous_indent_level, lines): r"""Separate top-level function and class definitions with two blank lines. Method definitions inside a class are separated by a single blank line. Extra blank lines may be used (sparingly) to separate groups of related functions. Blank lines may be omitted between a bunch of related one-liners (e.g. a set of dummy implementations). Use blank lines in functions, sparingly, to indicate logical sections. Okay: def a():\n pass\n\n\ndef b():\n pass Okay: def a():\n pass\n\n\nasync def b():\n pass Okay: def a():\n pass\n\n\n# Foo\n# Bar\n\ndef b():\n pass Okay: default = 1\nfoo = 1 Okay: classify = 1\nfoo = 1 E301: class Foo:\n b = 0\n def bar():\n pass E302: def a():\n pass\n\ndef b(n):\n pass E302: def a():\n pass\n\nasync def b(n):\n pass E303: def a():\n pass\n\n\n\ndef b(n):\n pass E303: def a():\n\n\n\n pass E304: @decorator\n\ndef a():\n pass E305: def a():\n pass\na() E306: def a():\n def b():\n pass\n def c():\n pass """ if line_number < 3 and not previous_logical: return # Don't expect blank lines before the first line if previous_logical.startswith('@'): if blank_lines: yield 0, "E304 blank lines found after function decorator" elif blank_lines > 2 or (indent_level and blank_lines == 2): yield 0, "E303 too many blank lines (%d)" % blank_lines elif STARTSWITH_TOP_LEVEL_REGEX.match(logical_line): if indent_level: if not (blank_before or previous_indent_level < indent_level or DOCSTRING_REGEX.match(previous_logical)): ancestor_level = indent_level nested = False # Search backwards for a def ancestor or tree root (top level). for line in lines[line_number - 2::-1]: if line.strip() and expand_indent(line) < ancestor_level: ancestor_level = expand_indent(line) nested = line.lstrip().startswith('def ') if nested or ancestor_level == 0: break if nested: yield 0, "E306 expected 1 blank line before a " \ "nested definition, found 0" else: yield 0, "E301 expected 1 blank line, found 0" elif blank_before != 2: yield 0, "E302 expected 2 blank lines, found %d" % blank_before elif (logical_line and not indent_level and blank_before != 2 and previous_unindented_logical_line.startswith(('def ', 'class '))): yield 0, "E305 expected 2 blank lines after " \ "class or function definition, found %d" % blank_before @register_check def extraneous_whitespace(logical_line): r"""Avoid extraneous whitespace. Avoid extraneous whitespace in these situations: - Immediately inside parentheses, brackets or braces. - Immediately before a comma, semicolon, or colon. Okay: spam(ham[1], {eggs: 2}) E201: spam( ham[1], {eggs: 2}) E201: spam(ham[ 1], {eggs: 2}) E201: spam(ham[1], { eggs: 2}) E202: spam(ham[1], {eggs: 2} ) E202: spam(ham[1 ], {eggs: 2}) E202: spam(ham[1], {eggs: 2 }) E203: if x == 4: print x, y; x, y = y , x E203: if x == 4: print x, y ; x, y = y, x E203: if x == 4 : print x, y; x, y = y, x """ line = logical_line for match in EXTRANEOUS_WHITESPACE_REGEX.finditer(line): text = match.group() char = text.strip() found = match.start() if text == char + ' ': # assert char in '([{' yield found + 1, "E201 whitespace after '%s'" % char elif line[found - 1] != ',': code = ('E202' if char in '}])' else 'E203') # if char in ',;:' yield found, "%s whitespace before '%s'" % (code, char) @register_check def whitespace_around_keywords(logical_line): r"""Avoid extraneous whitespace around keywords. Okay: True and False E271: True and False E272: True and False E273: True and\tFalse E274: True\tand False """ for match in KEYWORD_REGEX.finditer(logical_line): before, after = match.groups() if '\t' in before: yield match.start(1), "E274 tab before keyword" elif len(before) > 1: yield match.start(1), "E272 multiple spaces before keyword" if '\t' in after: yield match.start(2), "E273 tab after keyword" elif len(after) > 1: yield match.start(2), "E271 multiple spaces after keyword" @register_check def missing_whitespace_after_import_keyword(logical_line): r"""Multiple imports in form from x import (a, b, c) should have space between import statement and parenthesised name list. Okay: from foo import (bar, baz) E275: from foo import(bar, baz) E275: from importable.module import(bar, baz) """ line = logical_line indicator = ' import(' if line.startswith('from '): found = line.find(indicator) if -1 < found: pos = found + len(indicator) - 1 yield pos, "E275 missing whitespace after keyword" @register_check def missing_whitespace(logical_line): r"""Each comma, semicolon or colon should be followed by whitespace. Okay: [a, b] Okay: (3,) Okay: a[1:4] Okay: a[:4] Okay: a[1:] Okay: a[1:4:2] E231: ['a','b'] E231: foo(bar,baz) E231: [{'a':'b'}] """ line = logical_line for index in range(len(line) - 1): char = line[index] if char in ',;:' and line[index + 1] not in WHITESPACE: before = line[:index] if char == ':' and before.count('[') > before.count(']') and \ before.rfind('{') < before.rfind('['): continue # Slice syntax, no space required if char == ',' and line[index + 1] == ')': continue # Allow tuple with only one element: (3,) yield index, "E231 missing whitespace after '%s'" % char @register_check def indentation(logical_line, previous_logical, indent_char, indent_level, previous_indent_level): r"""Use 4 spaces per indentation level. For really old code that you don't want to mess up, you can continue to use 8-space tabs. Okay: a = 1 Okay: if a == 0:\n a = 1 E111: a = 1 E114: # a = 1 Okay: for item in items:\n pass E112: for item in items:\npass E115: for item in items:\n# Hi\n pass Okay: a = 1\nb = 2 E113: a = 1\n b = 2 E116: a = 1\n # b = 2 """ c = 0 if logical_line else 3 tmpl = "E11%d %s" if logical_line else "E11%d %s (comment)" if indent_level % 4: yield 0, tmpl % (1 + c, "indentation is not a multiple of four") indent_expect = previous_logical.endswith(':') if indent_expect and indent_level <= previous_indent_level: yield 0, tmpl % (2 + c, "expected an indented block") elif not indent_expect and indent_level > previous_indent_level: yield 0, tmpl % (3 + c, "unexpected indentation") @register_check def continued_indentation(logical_line, tokens, indent_level, hang_closing, indent_char, noqa, verbose): r"""Continuation lines indentation. Continuation lines should align wrapped elements either vertically using Python's implicit line joining inside parentheses, brackets and braces, or using a hanging indent. When using a hanging indent these considerations should be applied: - there should be no arguments on the first line, and - further indentation should be used to clearly distinguish itself as a continuation line. Okay: a = (\n) E123: a = (\n ) Okay: a = (\n 42) E121: a = (\n 42) E122: a = (\n42) E123: a = (\n 42\n ) E124: a = (24,\n 42\n) E125: if (\n b):\n pass E126: a = (\n 42) E127: a = (24,\n 42) E128: a = (24,\n 42) E129: if (a or\n b):\n pass E131: a = (\n 42\n 24) """ first_row = tokens[0][2][0] nrows = 1 + tokens[-1][2][0] - first_row if noqa or nrows == 1: return # indent_next tells us whether the next block is indented; assuming # that it is indented by 4 spaces, then we should not allow 4-space # indents on the final continuation line; in turn, some other # indents are allowed to have an extra 4 spaces. indent_next = logical_line.endswith(':') row = depth = 0 valid_hangs = (4,) if indent_char != '\t' else (4, 8) # remember how many brackets were opened on each line parens = [0] * nrows # relative indents of physical lines rel_indent = [0] * nrows # for each depth, collect a list of opening rows open_rows = [[0]] # for each depth, memorize the hanging indentation hangs = [None] # visual indents indent_chances = {} last_indent = tokens[0][2] visual_indent = None last_token_multiline = False # for each depth, memorize the visual indent column indent = [last_indent[1]] if verbose >= 3: print(">>> " + tokens[0][4].rstrip()) for token_type, text, start, end, line in tokens: newline = row < start[0] - first_row if newline: row = start[0] - first_row newline = not last_token_multiline and token_type not in NEWLINE if newline: # this is the beginning of a continuation line. last_indent = start if verbose >= 3: print("... " + line.rstrip()) # record the initial indent. rel_indent[row] = expand_indent(line) - indent_level # identify closing bracket close_bracket = (token_type == tokenize.OP and text in ']})') # is the indent relative to an opening bracket line? for open_row in reversed(open_rows[depth]): hang = rel_indent[row] - rel_indent[open_row] hanging_indent = hang in valid_hangs if hanging_indent: break if hangs[depth]: hanging_indent = (hang == hangs[depth]) # is there any chance of visual indent? visual_indent = (not close_bracket and hang > 0 and indent_chances.get(start[1])) if close_bracket and indent[depth]: # closing bracket for visual indent if start[1] != indent[depth]: yield (start, "E124 closing bracket does not match " "visual indentation") elif close_bracket and not hang: # closing bracket matches indentation of opening bracket's line if hang_closing: yield start, "E133 closing bracket is missing indentation" elif indent[depth] and start[1] < indent[depth]: if visual_indent is not True: # visual indent is broken yield (start, "E128 continuation line " "under-indented for visual indent") elif hanging_indent or (indent_next and rel_indent[row] == 8): # hanging indent is verified if close_bracket and not hang_closing: yield (start, "E123 closing bracket does not match " "indentation of opening bracket's line") hangs[depth] = hang elif visual_indent is True: # visual indent is verified indent[depth] = start[1] elif visual_indent in (text, str): # ignore token lined up with matching one from a previous line pass else: # indent is broken if hang <= 0: error = "E122", "missing indentation or outdented" elif indent[depth]: error = "E127", "over-indented for visual indent" elif not close_bracket and hangs[depth]: error = "E131", "unaligned for hanging indent" else: hangs[depth] = hang if hang > 4: error = "E126", "over-indented for hanging indent" else: error = "E121", "under-indented for hanging indent" yield start, "%s continuation line %s" % error # look for visual indenting if (parens[row] and token_type not in (tokenize.NL, tokenize.COMMENT) and not indent[depth]): indent[depth] = start[1] indent_chances[start[1]] = True if verbose >= 4: print("bracket depth %s indent to %s" % (depth, start[1])) # deal with implicit string concatenation elif (token_type in (tokenize.STRING, tokenize.COMMENT) or text in ('u', 'ur', 'b', 'br')): indent_chances[start[1]] = str # special case for the "if" statement because len("if (") == 4 elif not indent_chances and not row and not depth and text == 'if': indent_chances[end[1] + 1] = True elif text == ':' and line[end[1]:].isspace(): open_rows[depth].append(row) # keep track of bracket depth if token_type == tokenize.OP: if text in '([{': depth += 1 indent.append(0) hangs.append(None) if len(open_rows) == depth: open_rows.append([]) open_rows[depth].append(row) parens[row] += 1 if verbose >= 4: print("bracket depth %s seen, col %s, visual min = %s" % (depth, start[1], indent[depth])) elif text in ')]}' and depth > 0: # parent indents should not be more than this one prev_indent = indent.pop() or last_indent[1] hangs.pop() for d in range(depth): if indent[d] > prev_indent: indent[d] = 0 for ind in list(indent_chances): if ind >= prev_indent: del indent_chances[ind] del open_rows[depth + 1:] depth -= 1 if depth: indent_chances[indent[depth]] = True for idx in range(row, -1, -1): if parens[idx]: parens[idx] -= 1 break assert len(indent) == depth + 1 if start[1] not in indent_chances: # allow lining up tokens indent_chances[start[1]] = text last_token_multiline = (start[0] != end[0]) if last_token_multiline: rel_indent[end[0] - first_row] = rel_indent[row] if indent_next and expand_indent(line) == indent_level + 4: pos = (start[0], indent[0] + 4) if visual_indent: code = "E129 visually indented line" else: code = "E125 continuation line" yield pos, "%s with same indent as next logical line" % code @register_check def whitespace_before_parameters(logical_line, tokens): r"""Avoid extraneous whitespace. Avoid extraneous whitespace in the following situations: - before the open parenthesis that starts the argument list of a function call. - before the open parenthesis that starts an indexing or slicing. Okay: spam(1) E211: spam (1) Okay: dict['key'] = list[index] E211: dict ['key'] = list[index] E211: dict['key'] = list [index] """ prev_type, prev_text, __, prev_end, __ = tokens[0] for index in range(1, len(tokens)): token_type, text, start, end, __ = tokens[index] if (token_type == tokenize.OP and text in '([' and start != prev_end and (prev_type == tokenize.NAME or prev_text in '}])') and # Syntax "class A (B):" is allowed, but avoid it (index < 2 or tokens[index - 2][1] != 'class') and # Allow "return (a.foo for a in range(5))" not keyword.iskeyword(prev_text)): yield prev_end, "E211 whitespace before '%s'" % text prev_type = token_type prev_text = text prev_end = end @register_check def whitespace_around_operator(logical_line): r"""Avoid extraneous whitespace around an operator. Okay: a = 12 + 3 E221: a = 4 + 5 E222: a = 4 + 5 E223: a = 4\t+ 5 E224: a = 4 +\t5 """ for match in OPERATOR_REGEX.finditer(logical_line): before, after = match.groups() if '\t' in before: yield match.start(1), "E223 tab before operator" elif len(before) > 1: yield match.start(1), "E221 multiple spaces before operator" if '\t' in after: yield match.start(2), "E224 tab after operator" elif len(after) > 1: yield match.start(2), "E222 multiple spaces after operator" @register_check def missing_whitespace_around_operator(logical_line, tokens): r"""Surround operators with a single space on either side. - Always surround these binary operators with a single space on either side: assignment (=), augmented assignment (+=, -= etc.), comparisons (==, <, >, !=, <=, >=, in, not in, is, is not), Booleans (and, or, not). - If operators with different priorities are used, consider adding whitespace around the operators with the lowest priorities. Okay: i = i + 1 Okay: submitted += 1 Okay: x = x * 2 - 1 Okay: hypot2 = x * x + y * y Okay: c = (a + b) * (a - b) Okay: foo(bar, key='word', *args, **kwargs) Okay: alpha[:-i] E225: i=i+1 E225: submitted +=1 E225: x = x /2 - 1 E225: z = x **y E226: c = (a+b) * (a-b) E226: hypot2 = x*x + y*y E227: c = a|b E228: msg = fmt%(errno, errmsg) """ parens = 0 need_space = False prev_type = tokenize.OP prev_text = prev_end = None for token_type, text, start, end, line in tokens: if token_type in SKIP_COMMENTS: continue if text in ('(', 'lambda'): parens += 1 elif text == ')': parens -= 1 if need_space: if start != prev_end: # Found a (probably) needed space if need_space is not True and not need_space[1]: yield (need_space[0], "E225 missing whitespace around operator") need_space = False elif text == '>' and prev_text in ('<', '-'): # Tolerate the "<>" operator, even if running Python 3 # Deal with Python 3's annotated return value "->" pass else: if need_space is True or need_space[1]: # A needed trailing space was not found yield prev_end, "E225 missing whitespace around operator" elif prev_text != '**': code, optype = 'E226', 'arithmetic' if prev_text == '%': code, optype = 'E228', 'modulo' elif prev_text not in ARITHMETIC_OP: code, optype = 'E227', 'bitwise or shift' yield (need_space[0], "%s missing whitespace " "around %s operator" % (code, optype)) need_space = False elif token_type == tokenize.OP and prev_end is not None: if text == '=' and parens: # Allow keyword args or defaults: foo(bar=None). pass elif text in WS_NEEDED_OPERATORS: need_space = True elif text in UNARY_OPERATORS: # Check if the operator is being used as a binary operator # Allow unary operators: -123, -x, +1. # Allow argument unpacking: foo(*args, **kwargs). if (prev_text in '}])' if prev_type == tokenize.OP else prev_text not in KEYWORDS): need_space = None elif text in WS_OPTIONAL_OPERATORS: need_space = None if need_space is None: # Surrounding space is optional, but ensure that # trailing space matches opening space need_space = (prev_end, start != prev_end) elif need_space and start == prev_end: # A needed opening space was not found yield prev_end, "E225 missing whitespace around operator" need_space = False prev_type = token_type prev_text = text prev_end = end @register_check def whitespace_around_comma(logical_line): r"""Avoid extraneous whitespace after a comma or a colon. Note: these checks are disabled by default Okay: a = (1, 2) E241: a = (1, 2) E242: a = (1,\t2) """ line = logical_line for m in WHITESPACE_AFTER_COMMA_REGEX.finditer(line): found = m.start() + 1 if '\t' in m.group(): yield found, "E242 tab after '%s'" % m.group()[0] else: yield found, "E241 multiple spaces after '%s'" % m.group()[0] @register_check def whitespace_around_named_parameter_equals(logical_line, tokens): r"""Don't use spaces around the '=' sign in function arguments. Don't use spaces around the '=' sign when used to indicate a keyword argument or a default parameter value. Okay: def complex(real, imag=0.0): Okay: return magic(r=real, i=imag) Okay: boolean(a == b) Okay: boolean(a != b) Okay: boolean(a <= b) Okay: boolean(a >= b) Okay: def foo(arg: int = 42): Okay: async def foo(arg: int = 42): E251: def complex(real, imag = 0.0): E251: return magic(r = real, i = imag) """ parens = 0 no_space = False prev_end = None annotated_func_arg = False in_def = bool(STARTSWITH_DEF_REGEX.match(logical_line)) message = "E251 unexpected spaces around keyword / parameter equals" for token_type, text, start, end, line in tokens: if token_type == tokenize.NL: continue if no_space: no_space = False if start != prev_end: yield (prev_end, message) if token_type == tokenize.OP: if text in '([': parens += 1 elif text in ')]': parens -= 1 elif in_def and text == ':' and parens == 1: annotated_func_arg = True elif parens and text == ',' and parens == 1: annotated_func_arg = False elif parens and text == '=' and not annotated_func_arg: no_space = True if start != prev_end: yield (prev_end, message) if not parens: annotated_func_arg = False prev_end = end @register_check def whitespace_before_comment(logical_line, tokens): r"""Separate inline comments by at least two spaces. An inline comment is a comment on the same line as a statement. Inline comments should be separated by at least two spaces from the statement. They should start with a # and a single space. Each line of a block comment starts with a # and a single space (unless it is indented text inside the comment). Okay: x = x + 1 # Increment x Okay: x = x + 1 # Increment x Okay: # Block comment E261: x = x + 1 # Increment x E262: x = x + 1 #Increment x E262: x = x + 1 # Increment x E265: #Block comment E266: ### Block comment """ prev_end = (0, 0) for token_type, text, start, end, line in tokens: if token_type == tokenize.COMMENT: inline_comment = line[:start[1]].strip() if inline_comment: if prev_end[0] == start[0] and start[1] < prev_end[1] + 2: yield (prev_end, "E261 at least two spaces before inline comment") symbol, sp, comment = text.partition(' ') bad_prefix = symbol not in '#:' and (symbol.lstrip('#')[:1] or '#') if inline_comment: if bad_prefix or comment[:1] in WHITESPACE: yield start, "E262 inline comment should start with '# '" elif bad_prefix and (bad_prefix != '!' or start[0] > 1): if bad_prefix != '#': yield start, "E265 block comment should start with '# '" elif comment: yield start, "E266 too many leading '#' for block comment" elif token_type != tokenize.NL: prev_end = end @register_check def imports_on_separate_lines(logical_line): r"""Place imports on separate lines. Okay: import os\nimport sys E401: import sys, os Okay: from subprocess import Popen, PIPE Okay: from myclas import MyClass Okay: from foo.bar.yourclass import YourClass Okay: import myclass Okay: import foo.bar.yourclass """ line = logical_line if line.startswith('import '): found = line.find(',') if -1 < found and ';' not in line[:found]: yield found, "E401 multiple imports on one line" @register_check def module_imports_on_top_of_file( logical_line, indent_level, checker_state, noqa): r"""Place imports at the top of the file. Always put imports at the top of the file, just after any module comments and docstrings, and before module globals and constants. Okay: import os Okay: # this is a comment\nimport os Okay: '''this is a module docstring'''\nimport os Okay: r'''this is a module docstring'''\nimport os Okay: try:\n\timport x\nexcept ImportError:\n\tpass\nelse:\n\tpass\nimport y Okay: try:\n\timport x\nexcept ImportError:\n\tpass\nfinally:\n\tpass\nimport y E402: a=1\nimport os E402: 'One string'\n"Two string"\nimport os E402: a=1\nfrom sys import x Okay: if x:\n import os """ def is_string_literal(line): if line[0] in 'uUbB': line = line[1:] if line and line[0] in 'rR': line = line[1:] return line and (line[0] == '"' or line[0] == "'") allowed_try_keywords = ('try', 'except', 'else', 'finally') if indent_level: # Allow imports in conditional statements or functions return if not logical_line: # Allow empty lines or comments return if noqa: return line = logical_line if line.startswith('import ') or line.startswith('from '): if checker_state.get('seen_non_imports', False): yield 0, "E402 module level import not at top of file" elif re.match(DUNDER_REGEX, line): return elif any(line.startswith(kw) for kw in allowed_try_keywords): # Allow try, except, else, finally keywords intermixed with imports in # order to support conditional importing return elif is_string_literal(line): # The first literal is a docstring, allow it. Otherwise, report error. if checker_state.get('seen_docstring', False): checker_state['seen_non_imports'] = True else: checker_state['seen_docstring'] = True else: checker_state['seen_non_imports'] = True @register_check def compound_statements(logical_line): r"""Compound statements (on the same line) are generally discouraged. While sometimes it's okay to put an if/for/while with a small body on the same line, never do this for multi-clause statements. Also avoid folding such long lines! Always use a def statement instead of an assignment statement that binds a lambda expression directly to a name. Okay: if foo == 'blah':\n do_blah_thing() Okay: do_one() Okay: do_two() Okay: do_three() E701: if foo == 'blah': do_blah_thing() E701: for x in lst: total += x E701: while t < 10: t = delay() E701: if foo == 'blah': do_blah_thing() E701: else: do_non_blah_thing() E701: try: something() E701: finally: cleanup() E701: if foo == 'blah': one(); two(); three() E702: do_one(); do_two(); do_three() E703: do_four(); # useless semicolon E704: def f(x): return 2*x E731: f = lambda x: 2*x """ line = logical_line last_char = len(line) - 1 found = line.find(':') prev_found = 0 counts = dict((char, 0) for char in '{}[]()') while -1 < found < last_char: update_counts(line[prev_found:found], counts) if ((counts['{'] <= counts['}'] and # {'a': 1} (dict) counts['['] <= counts[']'] and # [1:2] (slice) counts['('] <= counts[')'])): # (annotation) lambda_kw = LAMBDA_REGEX.search(line, 0, found) if lambda_kw: before = line[:lambda_kw.start()].rstrip() if before[-1:] == '=' and isidentifier(before[:-1].strip()): yield 0, ("E731 do not assign a lambda expression, use a " "def") break if STARTSWITH_DEF_REGEX.match(line): yield 0, "E704 multiple statements on one line (def)" elif STARTSWITH_INDENT_STATEMENT_REGEX.match(line): yield found, "E701 multiple statements on one line (colon)" prev_found = found found = line.find(':', found + 1) found = line.find(';') while -1 < found: if found < last_char: yield found, "E702 multiple statements on one line (semicolon)" else: yield found, "E703 statement ends with a semicolon" found = line.find(';', found + 1) @register_check def explicit_line_join(logical_line, tokens): r"""Avoid explicit line join between brackets. The preferred way of wrapping long lines is by using Python's implied line continuation inside parentheses, brackets and braces. Long lines can be broken over multiple lines by wrapping expressions in parentheses. These should be used in preference to using a backslash for line continuation. E502: aaa = [123, \\n 123] E502: aaa = ("bbb " \\n "ccc") Okay: aaa = [123,\n 123] Okay: aaa = ("bbb "\n "ccc") Okay: aaa = "bbb " \\n "ccc" Okay: aaa = 123 # \\ """ prev_start = prev_end = parens = 0 comment = False backslash = None for token_type, text, start, end, line in tokens: if token_type == tokenize.COMMENT: comment = True if start[0] != prev_start and parens and backslash and not comment: yield backslash, "E502 the backslash is redundant between brackets" if end[0] != prev_end: if line.rstrip('\r\n').endswith('\\'): backslash = (end[0], len(line.splitlines()[-1]) - 1) else: backslash = None prev_start = prev_end = end[0] else: prev_start = start[0] if token_type == tokenize.OP: if text in '([{': parens += 1 elif text in ')]}': parens -= 1 @register_check def break_around_binary_operator(logical_line, tokens): r""" Avoid breaks before binary operators. The preferred place to break around a binary operator is after the operator, not before it. W503: (width == 0\n + height == 0) W503: (width == 0\n and height == 0) Okay: (width == 0 +\n height == 0) Okay: foo(\n -x) Okay: foo(x\n []) Okay: x = '''\n''' + '' Okay: foo(x,\n -y) Okay: foo(x, # comment\n -y) Okay: var = (1 &\n ~2) Okay: var = (1 /\n -2) Okay: var = (1 +\n -1 +\n -2) """ def is_binary_operator(token_type, text): # The % character is strictly speaking a binary operator, but the # common usage seems to be to put it next to the format parameters, # after a line break. return ((token_type == tokenize.OP or text in ['and', 'or']) and text not in "()[]{},:.;@=%~") line_break = False unary_context = True # Previous non-newline token types and text previous_token_type = None previous_text = None for token_type, text, start, end, line in tokens: if token_type == tokenize.COMMENT: continue if ('\n' in text or '\r' in text) and token_type != tokenize.STRING: line_break = True else: if (is_binary_operator(token_type, text) and line_break and not unary_context and not is_binary_operator(previous_token_type, previous_text)): yield start, "W503 line break before binary operator" unary_context = text in '([{,;' line_break = False previous_token_type = token_type previous_text = text @register_check def comparison_to_singleton(logical_line, noqa): r"""Comparison to singletons should use "is" or "is not". Comparisons to singletons like None should always be done with "is" or "is not", never the equality operators. Okay: if arg is not None: E711: if arg != None: E711: if None == arg: E712: if arg == True: E712: if False == arg: Also, beware of writing if x when you really mean if x is not None -- e.g. when testing whether a variable or argument that defaults to None was set to some other value. The other value might have a type (such as a container) that could be false in a boolean context! """ match = not noqa and COMPARE_SINGLETON_REGEX.search(logical_line) if match: singleton = match.group(1) or match.group(3) same = (match.group(2) == '==') msg = "'if cond is %s:'" % (('' if same else 'not ') + singleton) if singleton in ('None',): code = 'E711' else: code = 'E712' nonzero = ((singleton == 'True' and same) or (singleton == 'False' and not same)) msg += " or 'if %scond:'" % ('' if nonzero else 'not ') yield match.start(2), ("%s comparison to %s should be %s" % (code, singleton, msg)) @register_check def comparison_negative(logical_line): r"""Negative comparison should be done using "not in" and "is not". Okay: if x not in y:\n pass Okay: assert (X in Y or X is Z) Okay: if not (X in Y):\n pass Okay: zz = x is not y E713: Z = not X in Y E713: if not X.B in Y:\n pass E714: if not X is Y:\n pass E714: Z = not X.B is Y """ match = COMPARE_NEGATIVE_REGEX.search(logical_line) if match: pos = match.start(1) if match.group(2) == 'in': yield pos, "E713 test for membership should be 'not in'" else: yield pos, "E714 test for object identity should be 'is not'" @register_check def comparison_type(logical_line, noqa): r"""Object type comparisons should always use isinstance(). Do not compare types directly. Okay: if isinstance(obj, int): E721: if type(obj) is type(1): When checking if an object is a string, keep in mind that it might be a unicode string too! In Python 2.3, str and unicode have a common base class, basestring, so you can do: Okay: if isinstance(obj, basestring): Okay: if type(a1) is type(b1): """ match = COMPARE_TYPE_REGEX.search(logical_line) if match and not noqa: inst = match.group(1) if inst and isidentifier(inst) and inst not in SINGLETONS: return # Allow comparison for types which are not obvious yield match.start(), "E721 do not compare types, use 'isinstance()'" @register_check def bare_except(logical_line, noqa): r"""When catching exceptions, mention specific exceptions when possible. Okay: except Exception: Okay: except BaseException: E722: except: """ if noqa: return regex = re.compile(r"except\s*:") match = regex.match(logical_line) if match: yield match.start(), "E722 do not use bare 'except'" @register_check def ambiguous_identifier(logical_line, tokens): r"""Never use the characters 'l', 'O', or 'I' as variable names. In some fonts, these characters are indistinguishable from the numerals one and zero. When tempted to use 'l', use 'L' instead. Okay: L = 0 Okay: o = 123 Okay: i = 42 E741: l = 0 E741: O = 123 E741: I = 42 Variables can be bound in several other contexts, including class and function definitions, 'global' and 'nonlocal' statements, exception handlers, and 'with' statements. Okay: except AttributeError as o: Okay: with lock as L: E741: except AttributeError as O: E741: with lock as l: E741: global I E741: nonlocal l E742: class I(object): E743: def l(x): """ idents_to_avoid = ('l', 'O', 'I') prev_type, prev_text, prev_start, prev_end, __ = tokens[0] for token_type, text, start, end, line in tokens[1:]: ident = pos = None # identifiers on the lhs of an assignment operator if token_type == tokenize.OP and '=' in text: if prev_text in idents_to_avoid: ident = prev_text pos = prev_start # identifiers bound to a value with 'as', 'global', or 'nonlocal' if prev_text in ('as', 'global', 'nonlocal'): if text in idents_to_avoid: ident = text pos = start if prev_text == 'class': if text in idents_to_avoid: yield start, "E742 ambiguous class definition '%s'" % text if prev_text == 'def': if text in idents_to_avoid: yield start, "E743 ambiguous function definition '%s'" % text if ident: yield pos, "E741 ambiguous variable name '%s'" % ident prev_text = text prev_start = start @register_check def python_3000_has_key(logical_line, noqa): r"""The {}.has_key() method is removed in Python 3: use the 'in' operator. Okay: if "alph" in d:\n print d["alph"] W601: assert d.has_key('alph') """ pos = logical_line.find('.has_key(') if pos > -1 and not noqa: yield pos, "W601 .has_key() is deprecated, use 'in'" @register_check def python_3000_raise_comma(logical_line): r"""When raising an exception, use "raise ValueError('message')". The older form is removed in Python 3. Okay: raise DummyError("Message") W602: raise DummyError, "Message" """ match = RAISE_COMMA_REGEX.match(logical_line) if match and not RERAISE_COMMA_REGEX.match(logical_line): yield match.end() - 1, "W602 deprecated form of raising exception" @register_check def python_3000_not_equal(logical_line): r"""New code should always use != instead of <>. The older syntax is removed in Python 3. Okay: if a != 'no': W603: if a <> 'no': """ pos = logical_line.find('<>') if pos > -1: yield pos, "W603 '<>' is deprecated, use '!='" @register_check def python_3000_backticks(logical_line): r"""Use repr() instead of backticks in Python 3. Okay: val = repr(1 + 2) W604: val = `1 + 2` """ pos = logical_line.find('`') if pos > -1: yield pos, "W604 backticks are deprecated, use 'repr()'" @register_check def python_3000_invalid_escape_sequence(logical_line, tokens): r"""Invalid escape sequences are deprecated in Python 3.6. Okay: regex = r'\.png$' W605: regex = '\.png$' """ # https://docs.python.org/3/reference/lexical_analysis.html#string-and-bytes-literals valid = [ '\n', '\\', '\'', '"', 'a', 'b', 'f', 'n', 'r', 't', 'v', '0', '1', '2', '3', '4', '5', '6', '7', 'x', # Escape sequences only recognized in string literals 'N', 'u', 'U', ] for token_type, text, start, end, line in tokens: if token_type == tokenize.STRING: quote = text[-3:] if text[-3:] in ('"""', "'''") else text[-1] # Extract string modifiers (e.g. u or r) quote_pos = text.index(quote) prefix = text[:quote_pos].lower() start = quote_pos + len(quote) string = text[start:-len(quote)] if 'r' not in prefix: pos = string.find('\\') while pos >= 0: pos += 1 if string[pos] not in valid: yield ( pos, "W605 invalid escape sequence '\\%s'" % string[pos], ) pos = string.find('\\', pos + 1) ############################################################################## # Helper functions ############################################################################## if sys.version_info < (3,): # Python 2: implicit encoding. def readlines(filename): """Read the source code.""" with open(filename, 'rU') as f: return f.readlines() isidentifier = re.compile(r'[a-zA-Z_]\w*$').match stdin_get_value = sys.stdin.read else: # Python 3 def readlines(filename): """Read the source code.""" try: with open(filename, 'rb') as f: (coding, lines) = tokenize.detect_encoding(f.readline) f = TextIOWrapper(f, coding, line_buffering=True) return [line.decode(coding) for line in lines] + f.readlines() except (LookupError, SyntaxError, UnicodeError): # Fall back if file encoding is improperly declared with open(filename, encoding='latin-1') as f: return f.readlines() isidentifier = str.isidentifier def stdin_get_value(): """Read the value from stdin.""" return TextIOWrapper(sys.stdin.buffer, errors='ignore').read() noqa = lru_cache(512)(re.compile(r'# no(?:qa|pep8)\b', re.I).search)
[docs]def expand_indent(line): r"""Return the amount of indentation. Tabs are expanded to the next multiple of 8. >>> expand_indent(' ') 4 >>> expand_indent('\t') 8 >>> expand_indent(' \t') 8 >>> expand_indent(' \t') 16 """ if '\t' not in line: return len(line) - len(line.lstrip()) result = 0 for char in line: if char == '\t': result = result // 8 * 8 + 8 elif char == ' ': result += 1 else: break return result
[docs]def mute_string(text): """Replace contents with 'xxx' to prevent syntax matching. >>> mute_string('"abc"') '"xxx"' >>> mute_string("'''abc'''") "'''xxx'''" >>> mute_string("r'abc'") "r'xxx'" """ # String modifiers (e.g. u or r) start = text.index(text[-1]) + 1 end = len(text) - 1 # Triple quotes if text[-3:] in ('"""', "'''"): start += 2 end -= 2 return text[:start] + 'x' * (end - start) + text[end:]
def parse_udiff(diff, patterns=None, parent='.'): """Return a dictionary of matching lines.""" # For each file of the diff, the entry key is the filename, # and the value is a set of row numbers to consider. rv = {} path = nrows = None for line in diff.splitlines(): if nrows: if line[:1] != '-': nrows -= 1 continue if line[:3] == '@@ ': hunk_match = HUNK_REGEX.match(line) (row, nrows) = [int(g or '1') for g in hunk_match.groups()] rv[path].update(range(row, row + nrows)) elif line[:3] == '+++': path = line[4:].split('\t', 1)[0] if path[:2] == 'b/': path = path[2:] rv[path] = set() return dict([(os.path.join(parent, path), rows) for (path, rows) in rv.items() if rows and filename_match(path, patterns)]) def normalize_paths(value, parent=os.curdir): """Parse a comma-separated list of paths. Return a list of absolute paths. """ if not value: return [] if isinstance(value, list): return value paths = [] for path in value.split(','): path = path.strip() if '/' in path: path = os.path.abspath(os.path.join(parent, path)) paths.append(path.rstrip('/')) return paths def filename_match(filename, patterns, default=True): """Check if patterns contains a pattern that matches filename. If patterns is unspecified, this always returns True. """ if not patterns: return default return any(fnmatch(filename, pattern) for pattern in patterns) def update_counts(s, counts): r"""Adds one to the counts of each appearance of characters in s, for characters in counts""" for char in s: if char in counts: counts[char] += 1 def _is_eol_token(token): return token[0] in NEWLINE or token[4][token[3][1]:].lstrip() == '\\\n' if COMMENT_WITH_NL: def _is_eol_token(token, _eol_token=_is_eol_token): return _eol_token(token) or (token[0] == tokenize.COMMENT and token[1] == token[4]) ############################################################################## # Framework to run all checks ##############################################################################
[docs]class Checker(object): """Load a Python source file, tokenize it, check coding style.""" def __init__(self, filename=None, lines=None, options=None, report=None, **kwargs): if options is None: options = StyleGuide(kwargs).options else: assert not kwargs self._io_error = None self._physical_checks = options.physical_checks self._logical_checks = options.logical_checks self._ast_checks = options.ast_checks self.max_line_length = options.max_line_length self.multiline = False # in a multiline string? self.hang_closing = options.hang_closing self.verbose = options.verbose self.filename = filename # Dictionary where a checker can store its custom state. self._checker_states = {} if filename is None: self.filename = 'stdin' self.lines = lines or [] elif filename == '-': self.filename = 'stdin' self.lines = stdin_get_value().splitlines(True) elif lines is None: try: self.lines = readlines(filename) except IOError: (exc_type, exc) = sys.exc_info()[:2] self._io_error = '%s: %s' % (exc_type.__name__, exc) self.lines = [] else: self.lines = lines if self.lines: ord0 = ord(self.lines[0][0]) if ord0 in (0xef, 0xfeff): # Strip the UTF-8 BOM if ord0 == 0xfeff: self.lines[0] = self.lines[0][1:] elif self.lines[0][:3] == '\xef\xbb\xbf': self.lines[0] = self.lines[0][3:] self.report = report or options.report self.report_error = self.report.error self.noqa = False def report_invalid_syntax(self): """Check if the syntax is valid.""" (exc_type, exc) = sys.exc_info()[:2] if len(exc.args) > 1: offset = exc.args[1] if len(offset) > 2: offset = offset[1:3] else: offset = (1, 0) self.report_error(offset[0], offset[1] or 0, 'E901 %s: %s' % (exc_type.__name__, exc.args[0]), self.report_invalid_syntax)
[docs] def readline(self): """Get the next line from the input buffer.""" if self.line_number >= self.total_lines: return '' line = self.lines[self.line_number] self.line_number += 1 if self.indent_char is None and line[:1] in WHITESPACE: self.indent_char = line[0] return line
[docs] def run_check(self, check, argument_names): """Run a check plugin.""" arguments = [] for name in argument_names: arguments.append(getattr(self, name)) return check(*arguments)
def init_checker_state(self, name, argument_names): """Prepare custom state for the specific checker plugin.""" if 'checker_state' in argument_names: self.checker_state = self._checker_states.setdefault(name, {})
[docs] def check_physical(self, line): """Run all physical checks on a raw input line.""" self.physical_line = line for name, check, argument_names in self._physical_checks: self.init_checker_state(name, argument_names) result = self.run_check(check, argument_names) if result is not None: (offset, text) = result self.report_error(self.line_number, offset, text, check) if text[:4] == 'E101': self.indent_char = line[0]
[docs] def build_tokens_line(self): """Build a logical line from tokens.""" logical = [] comments = [] length = 0 prev_row = prev_col = mapping = None for token_type, text, start, end, line in self.tokens: if token_type in SKIP_TOKENS: continue if not mapping: mapping = [(0, start)] if token_type == tokenize.COMMENT: comments.append(text) continue if token_type == tokenize.STRING: text = mute_string(text) if prev_row: (start_row, start_col) = start if prev_row != start_row: # different row prev_text = self.lines[prev_row - 1][prev_col - 1] if prev_text == ',' or (prev_text not in '{[(' and text not in '}])'): text = ' ' + text elif prev_col != start_col: # different column text = line[prev_col:start_col] + text logical.append(text) length += len(text) mapping.append((length, end)) (prev_row, prev_col) = end self.logical_line = ''.join(logical) self.noqa = comments and noqa(''.join(comments)) return mapping
[docs] def check_logical(self): """Build a line from tokens and run all logical checks on it.""" self.report.increment_logical_line() mapping = self.build_tokens_line() if not mapping: return mapping_offsets = [offset for offset, _ in mapping] (start_row, start_col) = mapping[0][1] start_line = self.lines[start_row - 1] self.indent_level = expand_indent(start_line[:start_col]) if self.blank_before < self.blank_lines: self.blank_before = self.blank_lines if self.verbose >= 2: print(self.logical_line[:80].rstrip()) for name, check, argument_names in self._logical_checks: if self.verbose >= 4: print(' ' + name) self.init_checker_state(name, argument_names) for offset, text in self.run_check(check, argument_names) or (): if not isinstance(offset, tuple): # As mappings are ordered, bisecting is a fast way # to find a given offset in them. token_offset, pos = mapping[bisect.bisect_left( mapping_offsets, offset)] offset = (pos[0], pos[1] + offset - token_offset) self.report_error(offset[0], offset[1], text, check) if self.logical_line: self.previous_indent_level = self.indent_level self.previous_logical = self.logical_line if not self.indent_level: self.previous_unindented_logical_line = self.logical_line self.blank_lines = 0 self.tokens = []
[docs] def check_ast(self): """Build the file's AST and run all AST checks.""" try: tree = compile(''.join(self.lines), '', 'exec', PyCF_ONLY_AST) except (ValueError, SyntaxError, TypeError): return self.report_invalid_syntax() for name, cls, __ in self._ast_checks: checker = cls(tree, self.filename) for lineno, offset, text, check in checker.run(): if not self.lines or not noqa(self.lines[lineno - 1]): self.report_error(lineno, offset, text, check)
[docs] def generate_tokens(self): """Tokenize the file, run physical line checks and yield tokens.""" if self._io_error: self.report_error(1, 0, 'E902 %s' % self._io_error, readlines) tokengen = tokenize.generate_tokens(self.readline) try: for token in tokengen: if token[2][0] > self.total_lines: return self.noqa = token[4] and noqa(token[4]) self.maybe_check_physical(token) yield token except (SyntaxError, tokenize.TokenError): self.report_invalid_syntax()
def maybe_check_physical(self, token): """If appropriate (based on token), check current physical line(s).""" # Called after every token, but act only on end of line. if _is_eol_token(token): # Obviously, a newline token ends a single physical line. self.check_physical(token[4]) elif token[0] == tokenize.STRING and '\n' in token[1]: # Less obviously, a string that contains newlines is a # multiline string, either triple-quoted or with internal # newlines backslash-escaped. Check every physical line in the # string *except* for the last one: its newline is outside of # the multiline string, so we consider it a regular physical # line, and will check it like any other physical line. # # Subtleties: # - we don't *completely* ignore the last line; if it contains # the magical "# noqa" comment, we disable all physical # checks for the entire multiline string # - have to wind self.line_number back because initially it # points to the last line of the string, and we want # check_physical() to give accurate feedback if noqa(token[4]): return self.multiline = True self.line_number = token[2][0] _, src, (_, offset), _, _ = token src = self.lines[self.line_number - 1][:offset] + src for line in src.split('\n')[:-1]: self.check_physical(line + '\n') self.line_number += 1 self.multiline = False
[docs] def check_all(self, expected=None, line_offset=0): """Run all checks on the input file.""" self.report.init_file(self.filename, self.lines, expected, line_offset) self.total_lines = len(self.lines) if self._ast_checks: self.check_ast() self.line_number = 0 self.indent_char = None self.indent_level = self.previous_indent_level = 0 self.previous_logical = '' self.previous_unindented_logical_line = '' self.tokens = [] self.blank_lines = self.blank_before = 0 parens = 0 for token in self.generate_tokens(): self.tokens.append(token) token_type, text = token[0:2] if self.verbose >= 3: if token[2][0] == token[3][0]: pos = '[%s:%s]' % (token[2][1] or '', token[3][1]) else: pos = 'l.%s' % token[3][0] print('l.%s\t%s\t%s\t%r' % (token[2][0], pos, tokenize.tok_name[token[0]], text)) if token_type == tokenize.OP: if text in '([{': parens += 1 elif text in '}])': parens -= 1 elif not parens: if token_type in NEWLINE: if token_type == tokenize.NEWLINE: self.check_logical() self.blank_before = 0 elif len(self.tokens) == 1: # The physical line contains only this token. self.blank_lines += 1 del self.tokens[0] else: self.check_logical() elif COMMENT_WITH_NL and token_type == tokenize.COMMENT: if len(self.tokens) == 1: # The comment also ends a physical line token = list(token) token[1] = text.rstrip('\r\n') token[3] = (token[2][0], token[2][1] + len(token[1])) self.tokens = [tuple(token)] self.check_logical() if self.tokens: self.check_physical(self.lines[-1]) self.check_logical() return self.report.get_file_results()
[docs]class BaseReport(object): """Collect the results of the checks.""" print_filename = False def __init__(self, options): self._benchmark_keys = options.benchmark_keys self._ignore_code = options.ignore_code # Results self.elapsed = 0 self.total_errors = 0 self.counters = dict.fromkeys(self._benchmark_keys, 0) self.messages = {}
[docs] def start(self): """Start the timer.""" self._start_time = time.time()
[docs] def stop(self): """Stop the timer.""" self.elapsed = time.time() - self._start_time
[docs] def init_file(self, filename, lines, expected, line_offset): """Signal a new file.""" self.filename = filename self.lines = lines self.expected = expected or () self.line_offset = line_offset self.file_errors = 0 self.counters['files'] += 1 self.counters['physical lines'] += len(lines)
[docs] def increment_logical_line(self): """Signal a new logical line.""" self.counters['logical lines'] += 1
[docs] def error(self, line_number, offset, text, check): """Report an error, according to options.""" code = text[:4] if self._ignore_code(code): return if code in self.counters: self.counters[code] += 1 else: self.counters[code] = 1 self.messages[code] = text[5:] # Don't care about expected errors or warnings if code in self.expected: return if self.print_filename and not self.file_errors: print(self.filename) self.file_errors += 1 self.total_errors += 1 return code
[docs] def get_file_results(self): """Return the count of errors and warnings for this file.""" return self.file_errors
[docs] def get_count(self, prefix=''): """Return the total count of errors and warnings.""" return sum([self.counters[key] for key in self.messages if key.startswith(prefix)])
[docs] def get_statistics(self, prefix=''): """Get statistics for message codes that start with the prefix. prefix='' matches all errors and warnings prefix='E' matches all errors prefix='W' matches all warnings prefix='E4' matches all errors that have to do with imports """ return ['%-7s %s %s' % (self.counters[key], key, self.messages[key]) for key in sorted(self.messages) if key.startswith(prefix)]
[docs] def print_statistics(self, prefix=''): """Print overall statistics (number of errors and warnings).""" for line in self.get_statistics(prefix): print(line)
[docs] def print_benchmark(self): """Print benchmark numbers.""" print('%-7.2f %s' % (self.elapsed, 'seconds elapsed')) if self.elapsed: for key in self._benchmark_keys: print('%-7d %s per second (%d total)' % (self.counters[key] / self.elapsed, key, self.counters[key]))
[docs]class FileReport(BaseReport): """Collect the results of the checks and print only the filenames.""" print_filename = True
[docs]class StandardReport(BaseReport): """Collect and print the results of the checks.""" def __init__(self, options): super(StandardReport, self).__init__(options) self._fmt = REPORT_FORMAT.get(options.format.lower(), options.format) self._repeat = options.repeat self._show_source = options.show_source self._show_pep8 = options.show_pep8 def init_file(self, filename, lines, expected, line_offset): """Signal a new file.""" self._deferred_print = [] return super(StandardReport, self).init_file( filename, lines, expected, line_offset) def error(self, line_number, offset, text, check): """Report an error, according to options.""" code = super(StandardReport, self).error(line_number, offset, text, check) if code and (self.counters[code] == 1 or self._repeat): self._deferred_print.append( (line_number, offset, code, text[5:], check.__doc__)) return code def get_file_results(self): """Print the result and return the overall count for this file.""" self._deferred_print.sort() for line_number, offset, code, text, doc in self._deferred_print: print(self._fmt % { 'path': self.filename, 'row': self.line_offset + line_number, 'col': offset + 1, 'code': code, 'text': text, }) if self._show_source: if line_number > len(self.lines): line = '' else: line = self.lines[line_number - 1] print(line.rstrip()) print(re.sub(r'\S', ' ', line[:offset]) + '^') if self._show_pep8 and doc: print(' ' + doc.strip()) # stdout is block buffered when not stdout.isatty(). # line can be broken where buffer boundary since other processes # write to same file. # flush() after print() to avoid buffer boundary. # Typical buffer size is 8192. line written safely when # len(line) < 8192. sys.stdout.flush() return self.file_errors
[docs]class DiffReport(StandardReport): """Collect and print the results for the changed lines only.""" def __init__(self, options): super(DiffReport, self).__init__(options) self._selected = options.selected_lines def error(self, line_number, offset, text, check): if line_number not in self._selected[self.filename]: return return super(DiffReport, self).error(line_number, offset, text, check)
[docs]class StyleGuide(object): """Initialize a PEP-8 instance with few options.""" def __init__(self, *args, **kwargs): # build options from the command line self.checker_class = kwargs.pop('checker_class', Checker) parse_argv = kwargs.pop('parse_argv', False) config_file = kwargs.pop('config_file', False) parser = kwargs.pop('parser', None) # build options from dict options_dict = dict(*args, **kwargs) arglist = None if parse_argv else options_dict.get('paths', None) verbose = options_dict.get('verbose', None) options, self.paths = process_options( arglist, parse_argv, config_file, parser, verbose) if options_dict: options.__dict__.update(options_dict) if 'paths' in options_dict: self.paths = options_dict['paths'] self.runner = self.input_file self.options = options if not options.reporter: options.reporter = BaseReport if options.quiet else StandardReport options.select = tuple(options.select or ()) if not (options.select or options.ignore or options.testsuite or options.doctest) and DEFAULT_IGNORE: # The default choice: ignore controversial checks options.ignore = tuple(DEFAULT_IGNORE.split(',')) else: # Ignore all checks which are not explicitly selected options.ignore = ('',) if options.select else tuple(options.ignore) options.benchmark_keys = BENCHMARK_KEYS[:] options.ignore_code = self.ignore_code options.physical_checks = self.get_checks('physical_line') options.logical_checks = self.get_checks('logical_line') options.ast_checks = self.get_checks('tree') self.init_report()
[docs] def init_report(self, reporter=None): """Initialize the report instance.""" self.options.report = (reporter or self.options.reporter)(self.options) return self.options.report
[docs] def check_files(self, paths=None): """Run all checks on the paths.""" if paths is None: paths = self.paths report = self.options.report runner = self.runner report.start() try: for path in paths: if os.path.isdir(path): self.input_dir(path) elif not self.excluded(path): runner(path) except KeyboardInterrupt: print('... stopped') report.stop() return report
[docs] def input_file(self, filename, lines=None, expected=None, line_offset=0): """Run all checks on a Python source file.""" if self.options.verbose: print('checking %s' % filename) fchecker = self.checker_class( filename, lines=lines, options=self.options) return fchecker.check_all(expected=expected, line_offset=line_offset)
[docs] def input_dir(self, dirname): """Check all files in this directory and all subdirectories.""" dirname = dirname.rstrip('/') if self.excluded(dirname): return 0 counters = self.options.report.counters verbose = self.options.verbose filepatterns = self.options.filename runner = self.runner for root, dirs, files in os.walk(dirname): if verbose: print('directory ' + root) counters['directories'] += 1 for subdir in sorted(dirs): if self.excluded(subdir, root): dirs.remove(subdir) for filename in sorted(files): # contain a pattern that matches? if ((filename_match(filename, filepatterns) and not self.excluded(filename, root))): runner(os.path.join(root, filename))
[docs] def excluded(self, filename, parent=None): """Check if the file should be excluded. Check if 'options.exclude' contains a pattern that matches filename. """ if not self.options.exclude: return False basename = os.path.basename(filename) if filename_match(basename, self.options.exclude): return True if parent: filename = os.path.join(parent, filename) filename = os.path.abspath(filename) return filename_match(filename, self.options.exclude)
[docs] def ignore_code(self, code): """Check if the error code should be ignored. If 'options.select' contains a prefix of the error code, return False. Else, if 'options.ignore' contains a prefix of the error code, return True. """ if len(code) < 4 and any(s.startswith(code) for s in self.options.select): return False return (code.startswith(self.options.ignore) and not code.startswith(self.options.select))
[docs] def get_checks(self, argument_name): """Get all the checks for this category. Find all globally visible functions where the first argument name starts with argument_name and which contain selected tests. """ checks = [] for check, attrs in _checks[argument_name].items(): (codes, args) = attrs if any(not (code and self.ignore_code(code)) for code in codes): checks.append((check.__name__, check, args)) return sorted(checks)
def get_parser(prog='pycodestyle', version=__version__): """Create the parser for the program.""" parser = OptionParser(prog=prog, version=version, usage="%prog [options] input ...") parser.config_options = [ 'exclude', 'filename', 'select', 'ignore', 'max-line-length', 'hang-closing', 'count', 'format', 'quiet', 'show-pep8', 'show-source', 'statistics', 'verbose'] parser.add_option('-v', '--verbose', default=0, action='count', help="print status messages, or debug with -vv") parser.add_option('-q', '--quiet', default=0, action='count', help="report only file names, or nothing with -qq") parser.add_option('-r', '--repeat', default=True, action='store_true', help="(obsolete) show all occurrences of the same error") parser.add_option('--first', action='store_false', dest='repeat', help="show first occurrence of each error") parser.add_option('--exclude', metavar='patterns', default=DEFAULT_EXCLUDE, help="exclude files or directories which match these " "comma separated patterns (default: %default)") parser.add_option('--filename', metavar='patterns', default='*.py', help="when parsing directories, only check filenames " "matching these comma separated patterns " "(default: %default)") parser.add_option('--select', metavar='errors', default='', help="select errors and warnings (e.g. E,W6)") parser.add_option('--ignore', metavar='errors', default='', help="skip errors and warnings (e.g. E4,W) " "(default: %s)" % DEFAULT_IGNORE) parser.add_option('--show-source', action='store_true', help="show source code for each error") parser.add_option('--show-pep8', action='store_true', help="show text of PEP 8 for each error " "(implies --first)") parser.add_option('--statistics', action='store_true', help="count errors and warnings") parser.add_option('--count', action='store_true', help="print total number of errors and warnings " "to standard error and set exit code to 1 if " "total is not null") parser.add_option('--max-line-length', type='int', metavar='n', default=MAX_LINE_LENGTH, help="set maximum allowed line length " "(default: %default)") parser.add_option('--hang-closing', action='store_true', help="hang closing bracket instead of matching " "indentation of opening bracket's line") parser.add_option('--format', metavar='format', default='default', help="set the error format [default|pylint|<custom>]") parser.add_option('--diff', action='store_true', help="report changes only within line number ranges in " "the unified diff received on STDIN") group = parser.add_option_group("Testing Options") if os.path.exists(TESTSUITE_PATH): group.add_option('--testsuite', metavar='dir', help="run regression tests from dir") group.add_option('--doctest', action='store_true', help="run doctest on myself") group.add_option('--benchmark', action='store_true', help="measure processing speed") return parser
[docs]def read_config(options, args, arglist, parser): """Read and parse configurations. If a config file is specified on the command line with the "--config" option, then only it is used for configuration. Otherwise, the user configuration (~/.config/pycodestyle) and any local configurations in the current directory or above will be merged together (in that order) using the read method of ConfigParser. """ config = RawConfigParser() cli_conf = options.config local_dir = os.curdir if USER_CONFIG and os.path.isfile(USER_CONFIG): if options.verbose: print('user configuration: %s' % USER_CONFIG) config.read(USER_CONFIG) parent = tail = args and os.path.abspath(os.path.commonprefix(args)) while tail: if config.read(os.path.join(parent, fn) for fn in PROJECT_CONFIG): local_dir = parent if options.verbose: print('local configuration: in %s' % parent) break (parent, tail) = os.path.split(parent) if cli_conf and os.path.isfile(cli_conf): if options.verbose: print('cli configuration: %s' % cli_conf) config.read(cli_conf) pycodestyle_section = None if config.has_section(parser.prog): pycodestyle_section = parser.prog elif config.has_section('pep8'): pycodestyle_section = 'pep8' # Deprecated warnings.warn('[pep8] section is deprecated. Use [pycodestyle].') if pycodestyle_section: option_list = dict([(o.dest, o.type or o.action) for o in parser.option_list]) # First, read the default values (new_options, __) = parser.parse_args([]) # Second, parse the configuration for opt in config.options(pycodestyle_section): if opt.replace('_', '-') not in parser.config_options: print(" unknown option '%s' ignored" % opt) continue if options.verbose > 1: print(" %s = %s" % (opt, config.get(pycodestyle_section, opt))) normalized_opt = opt.replace('-', '_') opt_type = option_list[normalized_opt] if opt_type in ('int', 'count'): value = config.getint(pycodestyle_section, opt) elif opt_type in ('store_true', 'store_false'): value = config.getboolean(pycodestyle_section, opt) else: value = config.get(pycodestyle_section, opt) if normalized_opt == 'exclude': value = normalize_paths(value, local_dir) setattr(new_options, normalized_opt, value) # Third, overwrite with the command-line options (options, __) = parser.parse_args(arglist, values=new_options) options.doctest = options.testsuite = False return options
[docs]def process_options(arglist=None, parse_argv=False, config_file=None, parser=None, verbose=None): """Process options passed either via arglist or via command line args. Passing in the ``config_file`` parameter allows other tools, such as flake8 to specify their own options to be processed in pycodestyle. """ if not parser: parser = get_parser() if not parser.has_option('--config'): group = parser.add_option_group("Configuration", description=( "The project options are read from the [%s] section of the " "tox.ini file or the setup.cfg file located in any parent folder " "of the path(s) being processed. Allowed options are: %s." % (parser.prog, ', '.join(parser.config_options)))) group.add_option('--config', metavar='path', default=config_file, help="user config file location") # Don't read the command line if the module is used as a library. if not arglist and not parse_argv: arglist = [] # If parse_argv is True and arglist is None, arguments are # parsed from the command line (sys.argv) (options, args) = parser.parse_args(arglist) options.reporter = None # If explicity specified verbosity, override any `-v` CLI flag if verbose is not None: options.verbose = verbose if options.ensure_value('testsuite', False): args.append(options.testsuite) elif not options.ensure_value('doctest', False): if parse_argv and not args: if options.diff or any(os.path.exists(name) for name in PROJECT_CONFIG): args = ['.'] else: parser.error('input not specified') options = read_config(options, args, arglist, parser) options.reporter = parse_argv and options.quiet == 1 and FileReport options.filename = _parse_multi_options(options.filename) options.exclude = normalize_paths(options.exclude) options.select = _parse_multi_options(options.select) options.ignore = _parse_multi_options(options.ignore) if options.diff: options.reporter = DiffReport stdin = stdin_get_value() options.selected_lines = parse_udiff(stdin, options.filename, args[0]) args = sorted(options.selected_lines) return options, args
def _parse_multi_options(options, split_token=','): r"""Split and strip and discard empties. Turns the following: A, B, into ["A", "B"] """ if options: return [o.strip() for o in options.split(split_token) if o.strip()] else: return options def _main(): """Parse options and run checks on Python source.""" import signal # Handle "Broken pipe" gracefully try: signal.signal(signal.SIGPIPE, lambda signum, frame: sys.exit(1)) except AttributeError: pass # not supported on Windows style_guide = StyleGuide(parse_argv=True) options = style_guide.options if options.doctest or options.testsuite: from testsuite.support import run_tests report = run_tests(style_guide) else: report = style_guide.check_files() if options.statistics: report.print_statistics() if options.benchmark: report.print_benchmark() if options.testsuite and not options.quiet: report.print_results() if report.total_errors: if options.count: sys.stderr.write(str(report.total_errors) + '\n') sys.exit(1) if __name__ == '__main__': _main()