Fix issue #400: Require two blank lines after toplevel def, class

Author: benesch

CHANGES.txt

@@ -26,6 +26,7 @@ Changes:
 * Added check E275 for whitespace on `from ... import ...` lines; #489 / #491
 * Added W503 to the list of codes ignored by default ignore list; #498
 * Removed use of project level `.pep8` configuration file; #364
+* Added check E305 for two blank lines after toplevel method and toplevel class; #400
 
 Bugs:
 

docs/intro.rst

@@ -322,6 +322,8 @@ This is the current list of error and warning codes:
 +------------+----------------------------------------------------------------------+
 | E304       | blank lines found after function decorator                           |
 +------------+----------------------------------------------------------------------+
+| E305       | expected 2 blank lines after end of function or class                |
++------------+----------------------------------------------------------------------+
 +------------+----------------------------------------------------------------------+
 | **E4**     | *Import*                                                             |
 +------------+----------------------------------------------------------------------+

pycodestyle.py

@@ -237,7 +237,8 @@ def maximum_line_length(physical_line, max_line_length, multiline, noqa):
 
 
 def blank_lines(logical_line, blank_lines, indent_level, line_number,
-                blank_before, previous_logical, previous_indent_level):
+                blank_before, previous_logical, previous_logical_toplevel,
+                previous_indent_level):
     r"""Separate top-level function and class definitions with two blank lines.
 
     Method definitions inside a class are separated by a single blank line.
@@ -256,6 +257,7 @@ def blank_lines(logical_line, blank_lines, indent_level, line_number,
     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()
     """
     if line_number < 3 and not previous_logical:
         return  # Don't expect blank lines before the first line
@@ -271,6 +273,10 @@ def blank_lines(logical_line, blank_lines, indent_level, line_number,
                 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_logical_toplevel.startswith(('def', 'class'))):
+        yield 0, "E305 expected 2 blank lines after " \
+            "class or function definition, found %d" % blank_before
 
 
 def extraneous_whitespace(logical_line):
@@ -1450,6 +1456,8 @@ def init_checks_registry():
     mod = inspect.getmodule(register_check)
     for (name, function) in inspect.getmembers(mod, inspect.isfunction):
         register_check(function)
+
+
 init_checks_registry()
 
 
@@ -1608,6 +1616,8 @@ def check_logical(self):
         if self.logical_line:
             self.previous_indent_level = self.indent_level
             self.previous_logical = self.logical_line
+            if not self.indent_level:
+                self.previous_logical_toplevel = self.logical_line
         self.blank_lines = 0
         self.tokens = []
 
@@ -1678,6 +1688,7 @@ def check_all(self, expected=None, line_offset=0):
         self.indent_char = None
         self.indent_level = self.previous_indent_level = 0
         self.previous_logical = ''
+        self.previous_logical_toplevel = ''
         self.tokens = []
         self.blank_lines = self.blank_before = 0
         parens = 0

testsuite/E12not.py

@@ -139,6 +139,7 @@ def long_function_name(
         var_four):
     print(var_one)
 
+
 if ((row < 0 or self.moduleCount <= row or
      col < 0 or self.moduleCount <= col)):
     raise Exception("%s,%s - %s" % (row, col, self.moduleCount))
@@ -400,6 +401,7 @@ def unicode2html(s):
                             .replace('"', '&#34;')
                             .replace('\n', '<br>\n'))
 
+
 #
 parser.add_option('--count', action='store_true',
                   help="print total number of errors and warnings "
@@ -616,6 +618,7 @@ def other_example():
         for key, val in node.items()
     ))]
 
+
 foo([
     'bug'
 ])

testsuite/E22.py

@@ -150,6 +150,7 @@ def halves(n):
 def squares(n):
     return (i**2 for i in range(n))
 
+
 ENG_PREFIXES = {
     -6: "\u03bc",  # Greek letter mu
     -3: "m",

testsuite/E30.py

@@ -88,3 +88,32 @@ def function():
 It gives error E303: too many blank lines (3)
 """
 #:
+
+#: E305:7:1
+def a():
+    print
+
+    # comment
+
+    # another comment
+a()
+#: E305:8:1
+def a():
+    print
+
+    # comment
+
+    # another comment
+
+try:
+    a()
+except:
+    pass
+#: E305:5:1
+def a():
+    print
+
+# Two spaces before comments, too.
+if a():
+    a()
+#:

testsuite/support.py

@@ -196,5 +196,6 @@ def run_tests(style):
         init_tests(style)
     return style.check_files()
 
+
 # nose should not collect these functions
 init_tests.__test__ = run_tests.__test__ = False

testsuite/test_all.py

@@ -62,5 +62,6 @@ def suite():
 def _main():
     return unittest.TextTestRunner(verbosity=2).run(suite())
 
+
 if __name__ == '__main__':
     sys.exit(not _main())