src/eric7/Documentation/Source/eric7.Plugins.CheckerPlugins.CodeStyleChecker.pycodestyle.html

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<h1>eric7.Plugins.CheckerPlugins.CodeStyleChecker.pycodestyle</h1>

<h3>Global Attributes</h3>

<table>
<tr><td>ARITHMETIC_OP</td></tr><tr><td>ASSIGNMENT_EXPRESSION_OP</td></tr><tr><td>BENCHMARK_KEYS</td></tr><tr><td>BLANK_EXCEPT_REGEX</td></tr><tr><td>BLANK_LINES_CONFIG</td></tr><tr><td>COMPARE_NEGATIVE_REGEX</td></tr><tr><td>COMPARE_SINGLETON_REGEX</td></tr><tr><td>COMPARE_TYPE_REGEX</td></tr><tr><td>DEFAULT_EXCLUDE</td></tr><tr><td>DEFAULT_IGNORE</td></tr><tr><td>DOCSTRING_REGEX</td></tr><tr><td>DUNDER_REGEX</td></tr><tr><td>ERRORCODE_REGEX</td></tr><tr><td>EXTRANEOUS_WHITESPACE_REGEX</td></tr><tr><td>HUNK_REGEX</td></tr><tr><td>INDENT_REGEX</td></tr><tr><td>INDENT_SIZE</td></tr><tr><td>KEYWORDS</td></tr><tr><td>KEYWORD_REGEX</td></tr><tr><td>LAMBDA_REGEX</td></tr><tr><td>MAX_DOC_LENGTH</td></tr><tr><td>MAX_LINE_LENGTH</td></tr><tr><td>NEWLINE</td></tr><tr><td>OPERATOR_REGEX</td></tr><tr><td>PROJECT_CONFIG</td></tr><tr><td>PyCF_ONLY_AST</td></tr><tr><td>RAISE_COMMA_REGEX</td></tr><tr><td>REPORT_FORMAT</td></tr><tr><td>RERAISE_COMMA_REGEX</td></tr><tr><td>SINGLETONS</td></tr><tr><td>SKIP_COMMENTS</td></tr><tr><td>SKIP_TOKENS</td></tr><tr><td>STARTSWITH_DEF_REGEX</td></tr><tr><td>STARTSWITH_INDENT_STATEMENT_REGEX</td></tr><tr><td>STARTSWITH_TOP_LEVEL_REGEX</td></tr><tr><td>TESTSUITE_PATH</td></tr><tr><td>UNARY_OPERATORS</td></tr><tr><td>WHITESPACE</td></tr><tr><td>WHITESPACE_AFTER_COMMA_REGEX</td></tr><tr><td>WS_NEEDED_OPERATORS</td></tr><tr><td>WS_OPTIONAL_OPERATORS</td></tr><tr><td>_SYMBOLIC_OPS</td></tr><tr><td>__version__</td></tr><tr><td>_checks</td></tr><tr><td>noqa</td></tr>
</table>
<h3>Classes</h3>

<table>

<tr>
<td><a href="#BaseReport">BaseReport</a></td>
<td>Collect the results of the checks.</td>
</tr>
<tr>
<td><a href="#Checker">Checker</a></td>
<td>Load a Python source file, tokenize it, check coding style.</td>
</tr>
<tr>
<td><a href="#DiffReport">DiffReport</a></td>
<td>Collect and print the results for the changed lines only.</td>
</tr>
<tr>
<td><a href="#FileReport">FileReport</a></td>
<td>Collect the results of the checks and print the filenames.</td>
</tr>
<tr>
<td><a href="#StandardReport">StandardReport</a></td>
<td>Collect and print the results of the checks.</td>
</tr>
<tr>
<td><a href="#StyleGuide">StyleGuide</a></td>
<td>Initialize a PEP-8 instance with few options.</td>
</tr>
</table>
<h3>Functions</h3>

<table>

<tr>
<td><a href="#_add_check">_add_check</a></td>
<td></td>
</tr>
<tr>
<td><a href="#_break_around_binary_operators">_break_around_binary_operators</a></td>
<td>Private function to reduce duplication.</td>
</tr>
<tr>
<td><a href="#_get_parameters">_get_parameters</a></td>
<td></td>
</tr>
<tr>
<td><a href="#_is_binary_operator">_is_binary_operator</a></td>
<td></td>
</tr>
<tr>
<td><a href="#_is_eol_token">_is_eol_token</a></td>
<td></td>
</tr>
<tr>
<td><a href="#_is_one_liner">_is_one_liner</a></td>
<td></td>
</tr>
<tr>
<td><a href="#_main">_main</a></td>
<td>Parse options and run checks on Python source.</td>
</tr>
<tr>
<td><a href="#_parse_multi_options">_parse_multi_options</a></td>
<td>Split and strip and discard empties.</td>
</tr>
<tr>
<td><a href="#ambiguous_identifier">ambiguous_identifier</a></td>
<td>Never use the characters 'l', 'O', or 'I' as variable names.</td>
</tr>
<tr>
<td><a href="#bare_except">bare_except</a></td>
<td>When catching exceptions, mention specific exceptions when possible.</td>
</tr>
<tr>
<td><a href="#blank_lines">blank_lines</a></td>
<td>Separate top-level function and class definitions with two blank lines.</td>
</tr>
<tr>
<td><a href="#break_after_binary_operator">break_after_binary_operator</a></td>
<td>Avoid breaks after binary operators.</td>
</tr>
<tr>
<td><a href="#break_before_binary_operator">break_before_binary_operator</a></td>
<td>Avoid breaks before binary operators.</td>
</tr>
<tr>
<td><a href="#comparison_negative">comparison_negative</a></td>
<td>Negative comparison should be done using "not in" and "is not".</td>
</tr>
<tr>
<td><a href="#comparison_to_singleton">comparison_to_singleton</a></td>
<td>Comparison to singletons should use "is" or "is not".</td>
</tr>
<tr>
<td><a href="#comparison_type">comparison_type</a></td>
<td>Object type comparisons should always use isinstance().</td>
</tr>
<tr>
<td><a href="#compound_statements">compound_statements</a></td>
<td>Compound statements (on the same line) are generally discouraged.</td>
</tr>
<tr>
<td><a href="#continued_indentation">continued_indentation</a></td>
<td>Continuation lines indentation.</td>
</tr>
<tr>
<td><a href="#expand_indent">expand_indent</a></td>
<td>Return the amount of indentation.</td>
</tr>
<tr>
<td><a href="#explicit_line_join">explicit_line_join</a></td>
<td>Avoid explicit line join between brackets.</td>
</tr>
<tr>
<td><a href="#extraneous_whitespace">extraneous_whitespace</a></td>
<td>Avoid extraneous whitespace.</td>
</tr>
<tr>
<td><a href="#filename_match">filename_match</a></td>
<td>Check if patterns contains a pattern that matches filename.</td>
</tr>
<tr>
<td><a href="#get_parser">get_parser</a></td>
<td>Create the parser for the program.</td>
</tr>
<tr>
<td><a href="#imports_on_separate_lines">imports_on_separate_lines</a></td>
<td>Place imports on separate lines.</td>
</tr>
<tr>
<td><a href="#indentation">indentation</a></td>
<td>Use indent_size (PEP8 says 4) spaces per indentation level.</td>
</tr>
<tr>
<td><a href="#is_string_literal">is_string_literal</a></td>
<td></td>
</tr>
<tr>
<td><a href="#maximum_doc_length">maximum_doc_length</a></td>
<td>Limit all doc lines to a maximum of 72 characters.</td>
</tr>
<tr>
<td><a href="#maximum_line_length">maximum_line_length</a></td>
<td>Limit all lines to a maximum of 79 characters.</td>
</tr>
<tr>
<td><a href="#missing_whitespace">missing_whitespace</a></td>
<td>Each comma, semicolon or colon should be followed by whitespace.</td>
</tr>
<tr>
<td><a href="#missing_whitespace_after_keyword">missing_whitespace_after_keyword</a></td>
<td>Keywords should be followed by whitespace.</td>
</tr>
<tr>
<td><a href="#missing_whitespace_around_operator">missing_whitespace_around_operator</a></td>
<td>Surround operators with a single space on either side.</td>
</tr>
<tr>
<td><a href="#module_imports_on_top_of_file">module_imports_on_top_of_file</a></td>
<td>Place imports at the top of the file.</td>
</tr>
<tr>
<td><a href="#mute_string">mute_string</a></td>
<td>Replace contents with 'xxx' to prevent syntax matching.</td>
</tr>
<tr>
<td><a href="#normalize_paths">normalize_paths</a></td>
<td>Parse a comma-separated list of paths.</td>
</tr>
<tr>
<td><a href="#parse_udiff">parse_udiff</a></td>
<td>Return a dictionary of matching lines.</td>
</tr>
<tr>
<td><a href="#process_options">process_options</a></td>
<td>Process options passed either via arglist or command line args.</td>
</tr>
<tr>
<td><a href="#python_3000_async_await_keywords">python_3000_async_await_keywords</a></td>
<td>'async' and 'await' are reserved keywords starting at Python 3.7.</td>
</tr>
<tr>
<td><a href="#python_3000_backticks">python_3000_backticks</a></td>
<td>Use repr() instead of backticks in Python 3.</td>
</tr>
<tr>
<td><a href="#python_3000_has_key">python_3000_has_key</a></td>
<td>The {}.has_key() method is removed in Python 3: use the 'in' operator.</td>
</tr>
<tr>
<td><a href="#python_3000_invalid_escape_sequence">python_3000_invalid_escape_sequence</a></td>
<td>Invalid escape sequences are deprecated in Python 3.6.</td>
</tr>
<tr>
<td><a href="#python_3000_not_equal">python_3000_not_equal</a></td>
<td>New code should always use != instead of <>.</td>
</tr>
<tr>
<td><a href="#python_3000_raise_comma">python_3000_raise_comma</a></td>
<td>When raising an exception, use "raise ValueError('message')".</td>
</tr>
<tr>
<td><a href="#read_config">read_config</a></td>
<td>Read and parse configurations.</td>
</tr>
<tr>
<td><a href="#readlines">readlines</a></td>
<td>Read the source code.</td>
</tr>
<tr>
<td><a href="#register_check">register_check</a></td>
<td>Register a new check object.</td>
</tr>
<tr>
<td><a href="#stdin_get_value">stdin_get_value</a></td>
<td>Read the value from stdin.</td>
</tr>
<tr>
<td><a href="#tabs_obsolete">tabs_obsolete</a></td>
<td>On new projects, spaces-only are strongly recommended over tabs.</td>
</tr>
<tr>
<td><a href="#tabs_or_spaces">tabs_or_spaces</a></td>
<td>Never mix tabs and spaces.</td>
</tr>
<tr>
<td><a href="#trailing_blank_lines">trailing_blank_lines</a></td>
<td>Trailing blank lines are superfluous.</td>
</tr>
<tr>
<td><a href="#trailing_whitespace">trailing_whitespace</a></td>
<td>Trailing whitespace is superfluous.</td>
</tr>
<tr>
<td><a href="#update_counts">update_counts</a></td>
<td>Adds one to the counts of each appearance of characters in s, for characters in counts</td>
</tr>
<tr>
<td><a href="#whitespace_around_comma">whitespace_around_comma</a></td>
<td>Avoid extraneous whitespace after a comma or a colon.</td>
</tr>
<tr>
<td><a href="#whitespace_around_keywords">whitespace_around_keywords</a></td>
<td>Avoid extraneous whitespace around keywords.</td>
</tr>
<tr>
<td><a href="#whitespace_around_named_parameter_equals">whitespace_around_named_parameter_equals</a></td>
<td>Don't use spaces around the '=' sign in function arguments.</td>
</tr>
<tr>
<td><a href="#whitespace_around_operator">whitespace_around_operator</a></td>
<td>Avoid extraneous whitespace around an operator.</td>
</tr>
<tr>
<td><a href="#whitespace_before_comment">whitespace_before_comment</a></td>
<td>Separate inline comments by at least two spaces.</td>
</tr>
<tr>
<td><a href="#whitespace_before_parameters">whitespace_before_parameters</a></td>
<td>Avoid extraneous whitespace.</td>
</tr>
</table>
<hr />
<hr />
<a NAME="BaseReport" ID="BaseReport"></a>
<h2>BaseReport</h2>

<p>
Collect the results of the checks.
</p>
<h3>Derived from</h3>
None
<h3>Class Attributes</h3>

<table>
<tr><td>print_filename</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>

<tr>
<td><a href="#BaseReport.__init__">BaseReport</a></td>
<td></td>
</tr>
<tr>
<td><a href="#BaseReport.error">error</a></td>
<td>Report an error, according to options.</td>
</tr>
<tr>
<td><a href="#BaseReport.error_args">error_args</a></td>
<td>Report an error, according to options.</td>
</tr>
<tr>
<td><a href="#BaseReport.get_count">get_count</a></td>
<td>Return the total count of errors and warnings.</td>
</tr>
<tr>
<td><a href="#BaseReport.get_file_results">get_file_results</a></td>
<td>Return the count of errors and warnings for this file.</td>
</tr>
<tr>
<td><a href="#BaseReport.get_statistics">get_statistics</a></td>
<td>Get statistics for message codes that start with the prefix.</td>
</tr>
<tr>
<td><a href="#BaseReport.increment_logical_line">increment_logical_line</a></td>
<td>Signal a new logical line.</td>
</tr>
<tr>
<td><a href="#BaseReport.init_file">init_file</a></td>
<td>Signal a new file.</td>
</tr>
<tr>
<td><a href="#BaseReport.print_benchmark">print_benchmark</a></td>
<td>Print benchmark numbers.</td>
</tr>
<tr>
<td><a href="#BaseReport.print_statistics">print_statistics</a></td>
<td>Print overall statistics (number of errors and warnings).</td>
</tr>
<tr>
<td><a href="#BaseReport.start">start</a></td>
<td>Start the timer.</td>
</tr>
<tr>
<td><a href="#BaseReport.stop">stop</a></td>
<td>Stop the timer.</td>
</tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<a NAME="BaseReport.__init__" ID="BaseReport.__init__"></a>
<h4>BaseReport (Constructor)</h4>
<b>BaseReport</b>(<i>options</i>)

<a NAME="BaseReport.error" ID="BaseReport.error"></a>
<h4>BaseReport.error</h4>
<b>error</b>(<i>line_number, offset, text, check</i>)

<p>
Report an error, according to options.
</p>
<a NAME="BaseReport.error_args" ID="BaseReport.error_args"></a>
<h4>BaseReport.error_args</h4>
<b>error_args</b>(<i>line_number, offset, text, check, *args</i>)

<p>
Report an error, according to options.
</p>
<a NAME="BaseReport.get_count" ID="BaseReport.get_count"></a>
<h4>BaseReport.get_count</h4>
<b>get_count</b>(<i>prefix=''</i>)

<p>
Return the total count of errors and warnings.
</p>
<a NAME="BaseReport.get_file_results" ID="BaseReport.get_file_results"></a>
<h4>BaseReport.get_file_results</h4>
<b>get_file_results</b>(<i></i>)

<p>
Return the count of errors and warnings for this file.
</p>
<a NAME="BaseReport.get_statistics" ID="BaseReport.get_statistics"></a>
<h4>BaseReport.get_statistics</h4>
<b>get_statistics</b>(<i>prefix=''</i>)

<p>
Get statistics for message codes that start with the prefix.
</p>
<p>
        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
</p>
<a NAME="BaseReport.increment_logical_line" ID="BaseReport.increment_logical_line"></a>
<h4>BaseReport.increment_logical_line</h4>
<b>increment_logical_line</b>(<i></i>)

<p>
Signal a new logical line.
</p>
<a NAME="BaseReport.init_file" ID="BaseReport.init_file"></a>
<h4>BaseReport.init_file</h4>
<b>init_file</b>(<i>filename, lines, expected, line_offset</i>)

<p>
Signal a new file.
</p>
<a NAME="BaseReport.print_benchmark" ID="BaseReport.print_benchmark"></a>
<h4>BaseReport.print_benchmark</h4>
<b>print_benchmark</b>(<i></i>)

<p>
Print benchmark numbers.
</p>
<a NAME="BaseReport.print_statistics" ID="BaseReport.print_statistics"></a>
<h4>BaseReport.print_statistics</h4>
<b>print_statistics</b>(<i>prefix=''</i>)

<p>
Print overall statistics (number of errors and warnings).
</p>
<a NAME="BaseReport.start" ID="BaseReport.start"></a>
<h4>BaseReport.start</h4>
<b>start</b>(<i></i>)

<p>
Start the timer.
</p>
<a NAME="BaseReport.stop" ID="BaseReport.stop"></a>
<h4>BaseReport.stop</h4>
<b>stop</b>(<i></i>)

<p>
Stop the timer.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="Checker" ID="Checker"></a>
<h2>Checker</h2>

<p>
Load a Python source file, tokenize it, check coding style.
</p>
<h3>Derived from</h3>
None
<h3>Class Attributes</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>

<tr>
<td><a href="#Checker.__init__">Checker</a></td>
<td></td>
</tr>
<tr>
<td><a href="#Checker.build_tokens_line">build_tokens_line</a></td>
<td>Build a logical line from tokens.</td>
</tr>
<tr>
<td><a href="#Checker.check_all">check_all</a></td>
<td>Run all checks on the input file.</td>
</tr>
<tr>
<td><a href="#Checker.check_ast">check_ast</a></td>
<td>Build the file's AST and run all AST checks.</td>
</tr>
<tr>
<td><a href="#Checker.check_logical">check_logical</a></td>
<td>Build a line from tokens and run all logical checks on it.</td>
</tr>
<tr>
<td><a href="#Checker.check_physical">check_physical</a></td>
<td>Run all physical checks on a raw input line.</td>
</tr>
<tr>
<td><a href="#Checker.generate_tokens">generate_tokens</a></td>
<td>Tokenize file, run physical line checks and yield tokens.</td>
</tr>
<tr>
<td><a href="#Checker.init_checker_state">init_checker_state</a></td>
<td>Prepare custom state for the specific checker plugin.</td>
</tr>
<tr>
<td><a href="#Checker.maybe_check_physical">maybe_check_physical</a></td>
<td>If appropriate for token, check current physical line(s).</td>
</tr>
<tr>
<td><a href="#Checker.readline">readline</a></td>
<td>Get the next line from the input buffer.</td>
</tr>
<tr>
<td><a href="#Checker.report_invalid_syntax">report_invalid_syntax</a></td>
<td>Check if the syntax is valid.</td>
</tr>
<tr>
<td><a href="#Checker.run_check">run_check</a></td>
<td>Run a check plugin.</td>
</tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<a NAME="Checker.__init__" ID="Checker.__init__"></a>
<h4>Checker (Constructor)</h4>
<b>Checker</b>(<i>filename=None, lines=None, options=None, report=None, **kwargs</i>)

<a NAME="Checker.build_tokens_line" ID="Checker.build_tokens_line"></a>
<h4>Checker.build_tokens_line</h4>
<b>build_tokens_line</b>(<i></i>)

<p>
Build a logical line from tokens.
</p>
<a NAME="Checker.check_all" ID="Checker.check_all"></a>
<h4>Checker.check_all</h4>
<b>check_all</b>(<i>expected=None, line_offset=0</i>)

<p>
Run all checks on the input file.
</p>
<a NAME="Checker.check_ast" ID="Checker.check_ast"></a>
<h4>Checker.check_ast</h4>
<b>check_ast</b>(<i></i>)

<p>
Build the file's AST and run all AST checks.
</p>
<a NAME="Checker.check_logical" ID="Checker.check_logical"></a>
<h4>Checker.check_logical</h4>
<b>check_logical</b>(<i></i>)

<p>
Build a line from tokens and run all logical checks on it.
</p>
<a NAME="Checker.check_physical" ID="Checker.check_physical"></a>
<h4>Checker.check_physical</h4>
<b>check_physical</b>(<i>line</i>)

<p>
Run all physical checks on a raw input line.
</p>
<a NAME="Checker.generate_tokens" ID="Checker.generate_tokens"></a>
<h4>Checker.generate_tokens</h4>
<b>generate_tokens</b>(<i></i>)

<p>
Tokenize file, run physical line checks and yield tokens.
</p>
<a NAME="Checker.init_checker_state" ID="Checker.init_checker_state"></a>
<h4>Checker.init_checker_state</h4>
<b>init_checker_state</b>(<i>name, argument_names</i>)

<p>
Prepare custom state for the specific checker plugin.
</p>
<a NAME="Checker.maybe_check_physical" ID="Checker.maybe_check_physical"></a>
<h4>Checker.maybe_check_physical</h4>
<b>maybe_check_physical</b>(<i>token, prev_physical</i>)

<p>
If appropriate for token, check current physical line(s).
</p>
<a NAME="Checker.readline" ID="Checker.readline"></a>
<h4>Checker.readline</h4>
<b>readline</b>(<i></i>)

<p>
Get the next line from the input buffer.
</p>
<a NAME="Checker.report_invalid_syntax" ID="Checker.report_invalid_syntax"></a>
<h4>Checker.report_invalid_syntax</h4>
<b>report_invalid_syntax</b>(<i></i>)

<p>
Check if the syntax is valid.
</p>
<a NAME="Checker.run_check" ID="Checker.run_check"></a>
<h4>Checker.run_check</h4>
<b>run_check</b>(<i>check, argument_names</i>)

<p>
Run a check plugin.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="DiffReport" ID="DiffReport"></a>
<h2>DiffReport</h2>

<p>
Collect and print the results for the changed lines only.
</p>
<h3>Derived from</h3>
StandardReport
<h3>Class Attributes</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>

<tr>
<td><a href="#DiffReport.__init__">DiffReport</a></td>
<td></td>
</tr>
<tr>
<td><a href="#DiffReport.error">error</a></td>
<td></td>
</tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<a NAME="DiffReport.__init__" ID="DiffReport.__init__"></a>
<h4>DiffReport (Constructor)</h4>
<b>DiffReport</b>(<i>options</i>)

<a NAME="DiffReport.error" ID="DiffReport.error"></a>
<h4>DiffReport.error</h4>
<b>error</b>(<i>line_number, offset, text, check</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="FileReport" ID="FileReport"></a>
<h2>FileReport</h2>

<p>
Collect the results of the checks and print the filenames.
</p>
<h3>Derived from</h3>
BaseReport
<h3>Class Attributes</h3>

<table>
<tr><td>print_filename</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="StandardReport" ID="StandardReport"></a>
<h2>StandardReport</h2>

<p>
Collect and print the results of the checks.
</p>
<h3>Derived from</h3>
BaseReport
<h3>Class Attributes</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>

<tr>
<td><a href="#StandardReport.__init__">StandardReport</a></td>
<td></td>
</tr>
<tr>
<td><a href="#StandardReport.error">error</a></td>
<td>Report an error, according to options.</td>
</tr>
<tr>
<td><a href="#StandardReport.error_args">error_args</a></td>
<td>Report an error, according to options.</td>
</tr>
<tr>
<td><a href="#StandardReport.get_file_results">get_file_results</a></td>
<td>Print results and return the overall count for this file.</td>
</tr>
<tr>
<td><a href="#StandardReport.init_file">init_file</a></td>
<td>Signal a new file.</td>
</tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<a NAME="StandardReport.__init__" ID="StandardReport.__init__"></a>
<h4>StandardReport (Constructor)</h4>
<b>StandardReport</b>(<i>options</i>)

<a NAME="StandardReport.error" ID="StandardReport.error"></a>
<h4>StandardReport.error</h4>
<b>error</b>(<i>line_number, offset, text, check</i>)

<p>
Report an error, according to options.
</p>
<a NAME="StandardReport.error_args" ID="StandardReport.error_args"></a>
<h4>StandardReport.error_args</h4>
<b>error_args</b>(<i>line_number, offset, code, check, *args</i>)

<p>
Report an error, according to options.
</p>
<a NAME="StandardReport.get_file_results" ID="StandardReport.get_file_results"></a>
<h4>StandardReport.get_file_results</h4>
<b>get_file_results</b>(<i></i>)

<p>
Print results and return the overall count for this file.
</p>
<a NAME="StandardReport.init_file" ID="StandardReport.init_file"></a>
<h4>StandardReport.init_file</h4>
<b>init_file</b>(<i>filename, lines, expected, line_offset</i>)

<p>
Signal a new file.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="StyleGuide" ID="StyleGuide"></a>
<h2>StyleGuide</h2>

<p>
Initialize a PEP-8 instance with few options.
</p>
<h3>Derived from</h3>
None
<h3>Class Attributes</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Class Methods</h3>

<table>
<tr><td>None</td></tr>
</table>
<h3>Methods</h3>

<table>

<tr>
<td><a href="#StyleGuide.__init__">StyleGuide</a></td>
<td></td>
</tr>
<tr>
<td><a href="#StyleGuide.check_files">check_files</a></td>
<td>Run all checks on the paths.</td>
</tr>
<tr>
<td><a href="#StyleGuide.excluded">excluded</a></td>
<td>Check if the file should be excluded.</td>
</tr>
<tr>
<td><a href="#StyleGuide.get_checks">get_checks</a></td>
<td>Get all the checks for this category.</td>
</tr>
<tr>
<td><a href="#StyleGuide.ignore_code">ignore_code</a></td>
<td>Check if the error code should be ignored.</td>
</tr>
<tr>
<td><a href="#StyleGuide.init_report">init_report</a></td>
<td>Initialize the report instance.</td>
</tr>
<tr>
<td><a href="#StyleGuide.input_dir">input_dir</a></td>
<td>Check all files in this directory and all subdirectories.</td>
</tr>
<tr>
<td><a href="#StyleGuide.input_file">input_file</a></td>
<td>Run all checks on a Python source file.</td>
</tr>
</table>
<h3>Static Methods</h3>

<table>
<tr><td>None</td></tr>
</table>

<a NAME="StyleGuide.__init__" ID="StyleGuide.__init__"></a>
<h4>StyleGuide (Constructor)</h4>
<b>StyleGuide</b>(<i>*args, **kwargs</i>)

<a NAME="StyleGuide.check_files" ID="StyleGuide.check_files"></a>
<h4>StyleGuide.check_files</h4>
<b>check_files</b>(<i>paths=None</i>)

<p>
Run all checks on the paths.
</p>
<a NAME="StyleGuide.excluded" ID="StyleGuide.excluded"></a>
<h4>StyleGuide.excluded</h4>
<b>excluded</b>(<i>filename, parent=None</i>)

<p>
Check if the file should be excluded.
</p>
<p>
        Check if 'options.exclude' contains a pattern matching filename.
</p>
<a NAME="StyleGuide.get_checks" ID="StyleGuide.get_checks"></a>
<h4>StyleGuide.get_checks</h4>
<b>get_checks</b>(<i>argument_name</i>)

<p>
Get all the checks for this category.
</p>
<p>
        Find all globally visible functions where the first argument
        name starts with argument_name and which contain selected tests.
</p>
<a NAME="StyleGuide.ignore_code" ID="StyleGuide.ignore_code"></a>
<h4>StyleGuide.ignore_code</h4>
<b>ignore_code</b>(<i>code</i>)

<p>
Check if the error code should be ignored.
</p>
<p>
        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.
</p>
<a NAME="StyleGuide.init_report" ID="StyleGuide.init_report"></a>
<h4>StyleGuide.init_report</h4>
<b>init_report</b>(<i>reporter=None</i>)

<p>
Initialize the report instance.
</p>
<a NAME="StyleGuide.input_dir" ID="StyleGuide.input_dir"></a>
<h4>StyleGuide.input_dir</h4>
<b>input_dir</b>(<i>dirname</i>)

<p>
Check all files in this directory and all subdirectories.
</p>
<a NAME="StyleGuide.input_file" ID="StyleGuide.input_file"></a>
<h4>StyleGuide.input_file</h4>
<b>input_file</b>(<i>filename, lines=None, expected=None, line_offset=0</i>)

<p>
Run all checks on a Python source file.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_add_check" ID="_add_check"></a>
<h2>_add_check</h2>
<b>_add_check</b>(<i>check, kind, codes, args</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_break_around_binary_operators" ID="_break_around_binary_operators"></a>
<h2>_break_around_binary_operators</h2>
<b>_break_around_binary_operators</b>(<i>tokens</i>)

<p>
Private function to reduce duplication.
</p>
<p>
    This factors out the shared details between
    :func:`break_before_binary_operator` and
    :func:`break_after_binary_operator`.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_get_parameters" ID="_get_parameters"></a>
<h2>_get_parameters</h2>
<b>_get_parameters</b>(<i>function</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_is_binary_operator" ID="_is_binary_operator"></a>
<h2>_is_binary_operator</h2>
<b>_is_binary_operator</b>(<i>token_type, text</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_is_eol_token" ID="_is_eol_token"></a>
<h2>_is_eol_token</h2>
<b>_is_eol_token</b>(<i>token</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_is_one_liner" ID="_is_one_liner"></a>
<h2>_is_one_liner</h2>
<b>_is_one_liner</b>(<i>logical_line, indent_level, lines, line_number</i>)

<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_main" ID="_main"></a>
<h2>_main</h2>
<b>_main</b>(<i></i>)

<p>
Parse options and run checks on Python source.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="_parse_multi_options" ID="_parse_multi_options"></a>
<h2>_parse_multi_options</h2>
<b>_parse_multi_options</b>(<i>options, split_token=', '</i>)

<p>
Split and strip and discard empties.
</p>
<p>
    Turns the following:
</p>
<p>
    A,
    B,
</p>
<p>
    into ["A", "B"]
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="ambiguous_identifier" ID="ambiguous_identifier"></a>
<h2>ambiguous_identifier</h2>
<b>ambiguous_identifier</b>(<i>logical_line, tokens</i>)

<p>
Never use the characters 'l', 'O', or 'I' as variable names.
</p>
<p>
    In some fonts, these characters are indistinguishable from the
    numerals one and zero. When tempted to use 'l', use 'L' instead.
</p>
<p>
    Okay: L = 0
    Okay: o = 123
    Okay: i = 42
    E741: l = 0
    E741: O = 123
    E741: I = 42
</p>
<p>
    Variables can be bound in several other contexts, including class
    and function definitions, lambda functions, 'global' and 'nonlocal'
    statements, exception handlers, and 'with' and 'for' statements.
    In addition, we have a special handling for function parameters.
</p>
<p>
    Okay: except AttributeError as o:
    Okay: with lock as L:
    Okay: foo(l=12)
    Okay: foo(l=I)
    Okay: for a in foo(l=12):
    Okay: lambda arg: arg * l
    Okay: lambda a=l[I:5]: None
    Okay: lambda x=a.I: None
    Okay: if l >= 12:
    E741: except AttributeError as O:
    E741: with lock as l:
    E741: global I
    E741: nonlocal l
    E741: def foo(l):
    E741: def foo(l=12):
    E741: l = foo(l=12)
    E741: for l in range(10):
    E741: [l for l in lines if l]
    E741: lambda l: None
    E741: lambda a=x[1:5], l: None
    E741: lambda **l:
    E741: def f(**l):
    E742: class I(object):
    E743: def l(x):
</p>
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<hr />
<hr />
<a NAME="bare_except" ID="bare_except"></a>
<h2>bare_except</h2>
<b>bare_except</b>(<i>logical_line, noqa</i>)

<p>
When catching exceptions, mention specific exceptions when
    possible.
</p>
<p>
    Okay: except Exception:
    Okay: except BaseException:
    E722: except:
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="blank_lines" ID="blank_lines"></a>
<h2>blank_lines</h2>
<b>blank_lines</b>(<i>logical_line, blank_lines, indent_level, line_number, blank_before, previous_logical, previous_unindented_logical_line, previous_indent_level, lines</i>)

<p>
Separate top-level function and class definitions with two blank
    lines.
</p>
<p>
    Method definitions inside a class are separated by a single blank
    line.
</p>
<p>
    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).
</p>
<p>
    Use blank lines in functions, sparingly, to indicate logical
    sections.
</p>
<p>
    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
</p>
<p>
    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
    E307: def a():\n    def b():\n        pass\n\n\n    def c():\n        pass
    E308: def a():\n\n\n\n    pass
</p>
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<hr />
<hr />
<a NAME="break_after_binary_operator" ID="break_after_binary_operator"></a>
<h2>break_after_binary_operator</h2>
<b>break_after_binary_operator</b>(<i>logical_line, tokens</i>)

<p>
    Avoid breaks after binary operators.
</p>
<p>
    The preferred place to break around a binary operator is before the
    operator, not after it.
</p>
<p>
    W504: (width == 0 +\n height == 0)
    W504: (width == 0 and\n height == 0)
    W504: var = (1 &\n       ~2)
</p>
<p>
    Okay: foo(\n    -x)
    Okay: foo(x\n    [])
    Okay: x = '''\n''' + ''
    Okay: x = '' + '''\n'''
    Okay: foo(x,\n    -y)
    Okay: foo(x,  # comment\n    -y)
</p>
<p>
    The following should be W504 but unary_context is tricky with these
    Okay: var = (1 /\n       -2)
    Okay: var = (1 +\n       -1 +\n       -2)
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="break_before_binary_operator" ID="break_before_binary_operator"></a>
<h2>break_before_binary_operator</h2>
<b>break_before_binary_operator</b>(<i>logical_line, tokens</i>)

<p>
    Avoid breaks before binary operators.
</p>
<p>
    The preferred place to break around a binary operator is after the
    operator, not before it.
</p>
<p>
    W503: (width == 0\n + height == 0)
    W503: (width == 0\n and height == 0)
    W503: var = (1\n       & ~2)
    W503: var = (1\n       / -2)
    W503: var = (1\n       + -1\n       + -2)
</p>
<p>
    Okay: foo(\n    -x)
    Okay: foo(x\n    [])
    Okay: x = '''\n''' + ''
    Okay: foo(x,\n    -y)
    Okay: foo(x,  # comment\n    -y)
</p>
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<hr />
<hr />
<a NAME="comparison_negative" ID="comparison_negative"></a>
<h2>comparison_negative</h2>
<b>comparison_negative</b>(<i>logical_line</i>)

<p>
Negative comparison should be done using "not in" and "is not".
</p>
<p>
    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
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="comparison_to_singleton" ID="comparison_to_singleton"></a>
<h2>comparison_to_singleton</h2>
<b>comparison_to_singleton</b>(<i>logical_line, noqa</i>)

<p>
Comparison to singletons should use "is" or "is not".
</p>
<p>
    Comparisons to singletons like None should always be done
    with "is" or "is not", never the equality operators.
</p>
<p>
    Okay: if arg is not None:
    E711: if arg != None:
    E711: if None == arg:
    E712: if arg == True:
    E712: if False == arg:
</p>
<p>
    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!
</p>
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<hr />
<hr />
<a NAME="comparison_type" ID="comparison_type"></a>
<h2>comparison_type</h2>
<b>comparison_type</b>(<i>logical_line, noqa</i>)

<p>
Object type comparisons should always use isinstance().
</p>
<p>
    Do not compare types directly.
</p>
<p>
    Okay: if isinstance(obj, int):
    E721: if type(obj) is type(1):
</p>
<p>
    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:
</p>
<p>
    Okay: if isinstance(obj, basestring):
    Okay: if type(a1) is type(b1):
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="compound_statements" ID="compound_statements"></a>
<h2>compound_statements</h2>
<b>compound_statements</b>(<i>logical_line</i>)

<p>
Compound statements (on the same line) are generally
    discouraged.
</p>
<p>
    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!
</p>
<p>
    Always use a def statement instead of an assignment statement that
    binds a lambda expression directly to a name.
</p>
<p>
    Okay: if foo == 'blah':\n    do_blah_thing()
    Okay: do_one()
    Okay: do_two()
    Okay: do_three()
</p>
<p>
    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
</p>
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<hr />
<hr />
<a NAME="continued_indentation" ID="continued_indentation"></a>
<h2>continued_indentation</h2>
<b>continued_indentation</b>(<i>logical_line, tokens, indent_level, hang_closing, indent_char, indent_size, noqa, verbose</i>)

<p>
Continuation lines indentation.
</p>
<p>
    Continuation lines should align wrapped elements either vertically
    using Python's implicit line joining inside parentheses, brackets
    and braces, or using a hanging indent.
</p>
<p>
    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.
</p>
<p>
    Okay: a = (\n)
    E123: a = (\n    )
</p>
<p>
    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)
</p>
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<hr />
<hr />
<a NAME="expand_indent" ID="expand_indent"></a>
<h2>expand_indent</h2>
<b>expand_indent</b>(<i>line</i>)

<p>
Return the amount of indentation.
</p>
<p>
    Tabs are expanded to the next multiple of 8.
</p>
<p>
    >>> expand_indent('    ')
    4
    >>> expand_indent('\t')
    8
    >>> expand_indent('       \t')
    8
    >>> expand_indent('        \t')
    16
</p>
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<hr />
<hr />
<a NAME="explicit_line_join" ID="explicit_line_join"></a>
<h2>explicit_line_join</h2>
<b>explicit_line_join</b>(<i>logical_line, tokens</i>)

<p>
Avoid explicit line join between brackets.
</p>
<p>
    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.
</p>
<p>
    E502: aaa = [123, \\n       123]
    E502: aaa = ("bbb " \\n       "ccc")
</p>
<p>
    Okay: aaa = [123,\n       123]
    Okay: aaa = ("bbb "\n       "ccc")
    Okay: aaa = "bbb " \\n    "ccc"
    Okay: aaa = 123  # \\
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="extraneous_whitespace" ID="extraneous_whitespace"></a>
<h2>extraneous_whitespace</h2>
<b>extraneous_whitespace</b>(<i>logical_line</i>)

<p>
Avoid extraneous whitespace.
</p>
<p>
    Avoid extraneous whitespace in these situations:
    - Immediately inside parentheses, brackets or braces.
    - Immediately before a comma, semicolon, or colon.
</p>
<p>
    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 })
</p>
<p>
    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
</p>
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<hr />
<hr />
<a NAME="filename_match" ID="filename_match"></a>
<h2>filename_match</h2>
<b>filename_match</b>(<i>filename, patterns, default=True</i>)

<p>
Check if patterns contains a pattern that matches filename.
</p>
<p>
    If patterns is unspecified, this always returns True.
</p>
<div align="right"><a href="#top">Up</a></div>
<hr />
<hr />
<a NAME="get_parser" ID="get_parser"></a>
<h2>get_parser</h2>
<b>get_parser</b>(<i>prog='pycodestyle', version=__version__</i>)

<p>
Create the parser for the program.
</p>
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<hr />
<hr />
<a NAME="imports_on_separate_lines" ID="imports_on_separate_lines"></a>
<h2>imports_on_separate_lines</h2>
<b>imports_on_separate_lines</b>(<i>logical_line</i>)

<p>
Place imports on separate lines.
</p>
<p>
    Okay: import os\nimport sys
    E401: import sys, os
</p>
<p>
    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
</p>
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<hr />
<hr />
<a NAME="indentation" ID="indentation"></a>
<h2>indentation</h2>
<b>indentation</b>(<i>logical_line, previous_logical, indent_char, indent_level, previous_indent_level, indent_size</i>)

<p>
Use indent_size (PEP8 says 4) spaces per indentation level.
</p>
<p>
    For really old code that you don't want to mess up, you can continue
    to use 8-space tabs.
</p>
<p>
    Okay: a = 1
    Okay: if a == 0:\n    a = 1
    E111:   a = 1
    E114:   # a = 1
</p>
<p>
    Okay: for item in items:\n    pass
    E112: for item in items:\npass
    E115: for item in items:\n# Hi\n    pass
</p>
<p>
    Okay: a = 1\nb = 2
    E113: a = 1\n    b = 2
    E116: a = 1\n    # b = 2
</p>
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<hr />
<hr />
<a NAME="is_string_literal" ID="is_string_literal"></a>
<h2>is_string_literal</h2>
<b>is_string_literal</b>(<i>line</i>)

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<hr />
<hr />
<a NAME="maximum_doc_length" ID="maximum_doc_length"></a>
<h2>maximum_doc_length</h2>
<b>maximum_doc_length</b>(<i>logical_line, max_doc_length, noqa, tokens</i>)

<p>
Limit all doc lines to a maximum of 72 characters.
</p>
<p>
    For flowing long blocks of text (docstrings or comments), limiting
    the length to 72 characters is recommended.
</p>
<p>
    Reports warning W505
</p>
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<hr />
<hr />
<a NAME="maximum_line_length" ID="maximum_line_length"></a>
<h2>maximum_line_length</h2>
<b>maximum_line_length</b>(<i>physical_line, max_line_length, multiline, line_number, noqa</i>)

<p>
Limit all lines to a maximum of 79 characters.
</p>
<p>
    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.
</p>
<p>
    Reports error E501.
</p>
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<hr />
<hr />
<a NAME="missing_whitespace" ID="missing_whitespace"></a>
<h2>missing_whitespace</h2>
<b>missing_whitespace</b>(<i>logical_line</i>)

<p>
Each comma, semicolon or colon should be followed by whitespace.
</p>
<p>
    Okay: [a, b]
    Okay: (3,)
    Okay: a[3,] = 1
    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'}]
</p>
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<hr />
<hr />
<a NAME="missing_whitespace_after_keyword" ID="missing_whitespace_after_keyword"></a>
<h2>missing_whitespace_after_keyword</h2>
<b>missing_whitespace_after_keyword</b>(<i>logical_line, tokens</i>)

<p>
Keywords should be followed by whitespace.
</p>
<p>
    Okay: from foo import (bar, baz)
    E275: from foo import(bar, baz)
    E275: from importable.module import(bar, baz)
    E275: if(foo): bar
</p>
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<hr />
<hr />
<a NAME="missing_whitespace_around_operator" ID="missing_whitespace_around_operator"></a>
<h2>missing_whitespace_around_operator</h2>
<b>missing_whitespace_around_operator</b>(<i>logical_line, tokens</i>)

<p>
Surround operators with a single space on either side.
</p>
<p>
    - 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).
</p>
<p>
    - If operators with different priorities are used, consider adding
      whitespace around the operators with the lowest priorities.
</p>
<p>
    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]
</p>
<p>
    E225: i=i+1
    E225: submitted +=1
    E225: x = x /2 - 1
    E225: z = x **y
    E225: z = 1and 1
    E226: c = (a+b) * (a-b)
    E226: hypot2 = x*x + y*y
    E227: c = a|b
    E228: msg = fmt%(errno, errmsg)
</p>
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<hr />
<hr />
<a NAME="module_imports_on_top_of_file" ID="module_imports_on_top_of_file"></a>
<h2>module_imports_on_top_of_file</h2>
<b>module_imports_on_top_of_file</b>(<i>logical_line, indent_level, checker_state, noqa</i>)

<p>
Place imports at the top of the file.
</p>
<p>
    Always put imports at the top of the file, just after any module
    comments and docstrings, and before module globals and constants.
</p>
<p>
    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
</p>
<p>
    Okay: if x:\n    import os
</p>
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<hr />
<hr />
<a NAME="mute_string" ID="mute_string"></a>
<h2>mute_string</h2>
<b>mute_string</b>(<i>text</i>)

<p>
Replace contents with 'xxx' to prevent syntax matching.
</p>
<p>
    >>> mute_string('"abc"')
    '"xxx"'
    >>> mute_string("'''abc'''")
    "'''xxx'''"
    >>> mute_string("r'abc'")
    "r'xxx'"
</p>
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<hr />
<hr />
<a NAME="normalize_paths" ID="normalize_paths"></a>
<h2>normalize_paths</h2>
<b>normalize_paths</b>(<i>value, parent=os.curdir</i>)

<p>
Parse a comma-separated list of paths.
</p>
<p>
    Return a list of absolute paths.
</p>
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<hr />
<hr />
<a NAME="parse_udiff" ID="parse_udiff"></a>
<h2>parse_udiff</h2>
<b>parse_udiff</b>(<i>diff, patterns=None, parent='.'</i>)

<p>
Return a dictionary of matching lines.
</p>
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<hr />
<hr />
<a NAME="process_options" ID="process_options"></a>
<h2>process_options</h2>
<b>process_options</b>(<i>arglist=None, parse_argv=False, config_file=None, parser=None, verbose=None</i>)

<p>
Process options passed either via arglist or command line args.
</p>
<p>
    Passing in the ``config_file`` parameter allows other tools, such as
    flake8 to specify their own options to be processed in pycodestyle.
</p>
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<hr />
<hr />
<a NAME="python_3000_async_await_keywords" ID="python_3000_async_await_keywords"></a>
<h2>python_3000_async_await_keywords</h2>
<b>python_3000_async_await_keywords</b>(<i>logical_line, tokens</i>)

<p>
'async' and 'await' are reserved keywords starting at Python 3.7.
</p>
<p>
    W606: async = 42
    W606: await = 42
    Okay: async def read(db):\n    data = await db.fetch('SELECT ...')
</p>
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<hr />
<hr />
<a NAME="python_3000_backticks" ID="python_3000_backticks"></a>
<h2>python_3000_backticks</h2>
<b>python_3000_backticks</b>(<i>logical_line</i>)

<p>
Use repr() instead of backticks in Python 3.
</p>
<p>
    Okay: val = repr(1 + 2)
    W604: val = `1 + 2`
</p>
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<hr />
<hr />
<a NAME="python_3000_has_key" ID="python_3000_has_key"></a>
<h2>python_3000_has_key</h2>
<b>python_3000_has_key</b>(<i>logical_line, noqa</i>)

<p>
The {}.has_key() method is removed in Python 3: use the 'in'
    operator.
</p>
<p>
    Okay: if "alph" in d:\n    print d["alph"]
    W601: assert d.has_key('alph')
</p>
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<hr />
<hr />
<a NAME="python_3000_invalid_escape_sequence" ID="python_3000_invalid_escape_sequence"></a>
<h2>python_3000_invalid_escape_sequence</h2>
<b>python_3000_invalid_escape_sequence</b>(<i>logical_line, tokens, noqa</i>)

<p>
Invalid escape sequences are deprecated in Python 3.6.
</p>
<p>
    Okay: regex = r'\.png$'
    W605: regex = '\.png$'
</p>
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<hr />
<hr />
<a NAME="python_3000_not_equal" ID="python_3000_not_equal"></a>
<h2>python_3000_not_equal</h2>
<b>python_3000_not_equal</b>(<i>logical_line</i>)

<p>
New code should always use != instead of <>.
</p>
<p>
    The older syntax is removed in Python 3.
</p>
<p>
    Okay: if a != 'no':
    W603: if a <> 'no':
</p>
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<hr />
<hr />
<a NAME="python_3000_raise_comma" ID="python_3000_raise_comma"></a>
<h2>python_3000_raise_comma</h2>
<b>python_3000_raise_comma</b>(<i>logical_line</i>)

<p>
When raising an exception, use "raise ValueError('message')".
</p>
<p>
    The older form is removed in Python 3.
</p>
<p>
    Okay: raise DummyError("Message")
    W602: raise DummyError, "Message"
</p>
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<hr />
<hr />
<a NAME="read_config" ID="read_config"></a>
<h2>read_config</h2>
<b>read_config</b>(<i>options, args, arglist, parser</i>)

<p>
Read and parse configurations.
</p>
<p>
    If a config file is specified on the command line with the
    "--config" option, then only it is used for configuration.
</p>
<p>
    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.
</p>
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<hr />
<hr />
<a NAME="readlines" ID="readlines"></a>
<h2>readlines</h2>
<b>readlines</b>(<i>filename</i>)

<p>
Read the source code.
</p>
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<hr />
<hr />
<a NAME="register_check" ID="register_check"></a>
<h2>register_check</h2>
<b>register_check</b>(<i>check, codes=None</i>)

<p>
Register a new check object.
</p>
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<hr />
<hr />
<a NAME="stdin_get_value" ID="stdin_get_value"></a>
<h2>stdin_get_value</h2>
<b>stdin_get_value</b>(<i></i>)

<p>
Read the value from stdin.
</p>
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<hr />
<hr />
<a NAME="tabs_obsolete" ID="tabs_obsolete"></a>
<h2>tabs_obsolete</h2>
<b>tabs_obsolete</b>(<i>physical_line</i>)

<p>
On new projects, spaces-only are strongly recommended over tabs.
</p>
<p>
    Okay: if True:\n    return
    W191: if True:\n\treturn
</p>
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<hr />
<hr />
<a NAME="tabs_or_spaces" ID="tabs_or_spaces"></a>
<h2>tabs_or_spaces</h2>
<b>tabs_or_spaces</b>(<i>physical_line, indent_char</i>)

<p>
Never mix tabs and spaces.
</p>
<p>
    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!
</p>
<p>
    Okay: if a == 0:\n    a = 1\n    b = 1
    E101: if a == 0:\n        a = 1\n\tb = 1
</p>
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<hr />
<hr />
<a NAME="trailing_blank_lines" ID="trailing_blank_lines"></a>
<h2>trailing_blank_lines</h2>
<b>trailing_blank_lines</b>(<i>physical_line, lines, line_number, total_lines</i>)

<p>
Trailing blank lines are superfluous.
</p>
<p>
    Okay: spam(1)
    W391: spam(1)\n
</p>
<p>
    However the last line should end with a new line (warning W292).
</p>
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<hr />
<hr />
<a NAME="trailing_whitespace" ID="trailing_whitespace"></a>
<h2>trailing_whitespace</h2>
<b>trailing_whitespace</b>(<i>physical_line</i>)

<p>
Trailing whitespace is superfluous.
</p>
<p>
    The warning returned varies on whether the line itself is blank,
    for easier filtering for those who want to indent their blank lines.
</p>
<p>
    Okay: spam(1)\n#
    W291: spam(1) \n#
    W293: class Foo(object):\n    \n    bang = 12
</p>
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<hr />
<hr />
<a NAME="update_counts" ID="update_counts"></a>
<h2>update_counts</h2>
<b>update_counts</b>(<i>s, counts</i>)

<p>
Adds one to the counts of each appearance of characters in s,
        for characters in counts
</p>
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<hr />
<hr />
<a NAME="whitespace_around_comma" ID="whitespace_around_comma"></a>
<h2>whitespace_around_comma</h2>
<b>whitespace_around_comma</b>(<i>logical_line</i>)

<p>
Avoid extraneous whitespace after a comma or a colon.
</p>
<p>
    Note: these checks are disabled by default
</p>
<p>
    Okay: a = (1, 2)
    E241: a = (1,  2)
    E242: a = (1,\t2)
</p>
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<hr />
<hr />
<a NAME="whitespace_around_keywords" ID="whitespace_around_keywords"></a>
<h2>whitespace_around_keywords</h2>
<b>whitespace_around_keywords</b>(<i>logical_line</i>)

<p>
Avoid extraneous whitespace around keywords.
</p>
<p>
    Okay: True and False
    E271: True and  False
    E272: True  and False
    E273: True and\tFalse
    E274: True\tand False
</p>
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<hr />
<hr />
<a NAME="whitespace_around_named_parameter_equals" ID="whitespace_around_named_parameter_equals"></a>
<h2>whitespace_around_named_parameter_equals</h2>
<b>whitespace_around_named_parameter_equals</b>(<i>logical_line, tokens</i>)

<p>
Don't use spaces around the '=' sign in function arguments.
</p>
<p>
    Don't use spaces around the '=' sign when used to indicate a
    keyword argument or a default parameter value, except when
    using a type annotation.
</p>
<p>
    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):
</p>
<p>
    E251: def complex(real, imag = 0.0):
    E251: return magic(r = real, i = imag)
    E252: def complex(real, image: float=0.0):
</p>
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<hr />
<hr />
<a NAME="whitespace_around_operator" ID="whitespace_around_operator"></a>
<h2>whitespace_around_operator</h2>
<b>whitespace_around_operator</b>(<i>logical_line</i>)

<p>
Avoid extraneous whitespace around an operator.
</p>
<p>
    Okay: a = 12 + 3
    E221: a = 4  + 5
    E222: a = 4 +  5
    E223: a = 4\t+ 5
    E224: a = 4 +\t5
</p>
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<hr />
<hr />
<a NAME="whitespace_before_comment" ID="whitespace_before_comment"></a>
<h2>whitespace_before_comment</h2>
<b>whitespace_before_comment</b>(<i>logical_line, tokens</i>)

<p>
Separate inline comments by at least two spaces.
</p>
<p>
    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.
</p>
<p>
    Each line of a block comment starts with a # and one or multiple
    spaces as there can be indented text inside the comment.
</p>
<p>
    Okay: x = x + 1  # Increment x
    Okay: x = x + 1    # Increment x
    Okay: # Block comments:
    Okay: #  - Block comment list
    Okay: # \xa0- Block comment list
    E261: x = x + 1 # Increment x
    E262: x = x + 1  #Increment x
    E262: x = x + 1  #  Increment x
    E262: x = x + 1  # \xa0Increment x
    E265: #Block comment
    E266: ### Block comment
</p>
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<hr />
<hr />
<a NAME="whitespace_before_parameters" ID="whitespace_before_parameters"></a>
<h2>whitespace_before_parameters</h2>
<b>whitespace_before_parameters</b>(<i>logical_line, tokens</i>)

<p>
Avoid extraneous whitespace.
</p>
<p>
    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.
</p>
<p>
    Okay: spam(1)
    E211: spam (1)
</p>
<p>
    Okay: dict['key'] = list[index]
    E211: dict ['key'] = list[index]
    E211: dict['key'] = list [index]
</p>
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<hr />
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