Support for custom indent sizes (tab widths) other than 4

docs/intro.rst

@@ -157,6 +157,7 @@ Quick help is available on the command line::
     --count              print total number of errors and warnings to standard
                          error and set exit code to 1 if total is not null
     --max-line-length=n  set maximum allowed line length (default: 79)
+    --indent-size=n      set how many spaces make up an indent (default: 4)
     --hang-closing       hang closing bracket instead of matching indentation of
                          opening bracket's line
     --format=format      set the error format [default|pylint|<custom>]

pycodestyle.py

@@ -82,6 +82,7 @@
 PROJECT_CONFIG = ('setup.cfg', 'tox.ini')
 TESTSUITE_PATH = os.path.join(os.path.dirname(__file__), 'testsuite')
 MAX_LINE_LENGTH = 79
+INDENT_SIZE = 4
 REPORT_FORMAT = {
     'default': '%(path)s:%(row)d:%(col)d: %(code)s %(text)s',
     'pylint': '%(path)s:%(row)d: [%(code)s] %(text)s',
@@ -371,8 +372,9 @@ def missing_whitespace(logical_line):
 
 
 def indentation(logical_line, previous_logical, indent_char,
-                indent_level, previous_indent_level):
-    r"""Use 4 spaces per indentation level.
+                indent_level, previous_indent_level,
+                indent_size):
+    r"""Use indent_size (PEP says 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.
@@ -392,8 +394,9 @@ def indentation(logical_line, previous_logical, indent_char,
     """
     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")
+    if indent_level % indent_size:
+        yield 0, tmpl % (1 + c,
+                         "indentation is not a multiple of %d" % indent_size)
     indent_expect = previous_logical.endswith(':')
     if indent_expect and indent_level <= previous_indent_level:
         yield 0, tmpl % (2 + c, "expected an indented block")
@@ -402,7 +405,7 @@ def indentation(logical_line, previous_logical, indent_char,
 
 
 def continued_indentation(logical_line, tokens, indent_level, hang_closing,
-                          indent_char, noqa, verbose):
+                          indent_char, indent_size, noqa, verbose):
     r"""Continuation lines indentation.
 
     Continuation lines should align wrapped elements either vertically
@@ -441,7 +444,8 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
     indent_next = logical_line.endswith(':')
 
     row = depth = 0
-    valid_hangs = (4,) if indent_char != '\t' else (4, 8)
+    valid_hangs = (indent_size,) if indent_char != '\t' \
+        else (indent_size, indent_size * 2)
     # remember how many brackets were opened on each line
     parens = [0] * nrows
     # relative indents of physical lines
@@ -505,7 +509,8 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
                     # 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):
+            elif hanging_indent or (indent_next and
+                                    rel_indent[row] == 2 * indent_size):
                 # hanging indent is verified
                 if close_bracket and not hang_closing:
                     yield (start, "E123 closing bracket does not match "
@@ -527,7 +532,7 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
                     error = "E131", "unaligned for hanging indent"
                 else:
                     hangs[depth] = hang
-                    if hang > 4:
+                    if hang > indent_size:
                         error = "E126", "over-indented for hanging indent"
                     else:
                         error = "E121", "under-indented for hanging indent"
@@ -1401,6 +1406,7 @@ def __init__(self, filename=None, lines=None,
         self._logical_checks = options.logical_checks
         self._ast_checks = options.ast_checks
         self.max_line_length = options.max_line_length
+        self.indent_size = options.indent_size
         self.multiline = False  # in a multiline string?
         self.hang_closing = options.hang_closing
         self.verbose = options.verbose
@@ -1958,7 +1964,7 @@ def get_parser(prog='pep8', version=__version__):
                           usage="%prog [options] input ...")
     parser.config_options = [
         'exclude', 'filename', 'select', 'ignore', 'max-line-length',
-        'hang-closing', 'count', 'format', 'quiet', 'show-pep8',
+        'indent_size', '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")
@@ -1995,6 +2001,10 @@ def get_parser(prog='pep8', version=__version__):
                       default=MAX_LINE_LENGTH,
                       help="set maximum allowed line length "
                            "(default: %default)")
+    parser.add_option('--indent-size', type='int', metavar='n',
+                      default=INDENT_SIZE,
+                      help="set how many spaces make up an indent "
+                           "(default: %default)")
     parser.add_option('--hang-closing', action='store_true',
                       help="hang closing bracket instead of matching "
                            "indentation of opening bracket's line")

testsuite/test_api.py

@@ -393,3 +393,52 @@ def test_styleguide_continuation_line_outdented(self):
 
         # TODO: runner
         # TODO: input_file
+
+    def test_styleguides_other_indent_size(self):
+        pycodestyle.register_check(DummyChecker, ['Z701'])
+        lines = [
+            'def foo():\n',
+            '    pass\n',
+            '\n',
+            '\n',
+            'def foo_correct():\n',
+            '   pass\n',
+            '\n',
+            '\n',
+            'def bar():\n',
+            '   [1, 2, 3,\n',
+            '     4, 5, 6,\n',
+            '     ]\n',
+            '\n',
+            '\n',
+            'if (1 in [1, 2, 3]\n',
+            '      and bool(0) is False\n',
+            '     and bool(1) is True):\n',
+            '   pass\n'
+        ]
+
+        pep8style = pycodestyle.StyleGuide()
+        pep8style.options.indent_size = 3
+        count_errors = pep8style.input_file('stdin', lines=lines)
+        stdout = sys.stdout.getvalue()
+        self.assertEqual(count_errors, 4)
+        expected = (
+            'stdin:2:5: '
+            'E111 indentation is not a multiple of 3'
+        )
+        self.assertTrue(expected in stdout)
+        expected = (
+            'stdin:11:6: '
+            'E127 continuation line over-indented for visual indent'
+        )
+        self.assertTrue(expected in stdout)
+        expected = (
+            'stdin:12:6: '
+            'E124 closing bracket does not match visual indentation'
+        )
+        self.assertTrue(expected in stdout)
+        expected = (
+            'stdin:17:6: '
+            'E127 continuation line over-indented for visual indent'
+        )
+        self.assertTrue(expected in stdout)