[skip ci] Integrate flake8 and flake8-rst into validate_docstrings.py

Signed-off-by: Fabian Haase <haase.fabian@gmail.com>

scripts/validate_docstrings.py

@@ -14,6 +14,7 @@
     $ ./validate_docstrings.py pandas.DataFrame.head
 """
 import os
+import subprocess
 import sys
 import json
 import re
@@ -24,6 +25,7 @@
 import inspect
 import importlib
 import doctest
+
 try:
     from io import StringIO
 except ImportError:
@@ -40,7 +42,6 @@
 from numpydoc.docscrape import NumpyDocString
 from pandas.io.formats.printing import pprint_thing
 
-
 PRIVATE_CLASSES = ['NDFrame', 'IndexOpsMixin']
 DIRECTIVES = ['versionadded', 'versionchanged', 'deprecated']
 
@@ -446,7 +447,7 @@ def validate_one(func_name):
         if doc.summary != doc.summary.lstrip():
             errs.append('Summary contains heading whitespaces.')
         elif (doc.is_function_or_method
-                and doc.summary.split(' ')[0][-1] == 's'):
+              and doc.summary.split(' ')[0][-1] == 's'):
             errs.append('Summary must start with infinitive verb, '
                         'not third person (e.g. use "Generate" instead of '
                         '"Generates")')
@@ -529,15 +530,16 @@ def validate_one(func_name):
         if examples_errs:
             errs.append('Examples do not pass tests')
 
-    return {'type': doc.type,
-            'docstring': doc.clean_doc,
-            'deprecated': doc.deprecated,
-            'file': doc.source_file_name,
-            'file_line': doc.source_file_def_line,
-            'github_link': doc.github_url,
-            'errors': errs,
-            'warnings': wrns,
-            'examples_errors': examples_errs}
+    return ({'type': doc.type,
+             'docstring': doc.clean_doc,
+             'deprecated': doc.deprecated,
+             'file': doc.source_file_name,
+             'file_line': doc.source_file_def_line,
+             'github_link': doc.github_url,
+             'errors': errs,
+             'warnings': wrns,
+             'examples_errors': examples_errs},
+            doc)
 
 
 def validate_all():
@@ -598,10 +600,15 @@ def header(title, width=80, char='#'):
             full_line=full_line, title_line=title_line)
 
     if func_name is None:
+        flake8 = _call_flake8_plugin()
+        if flake8:
+            fd.write('Flake8 reported issues:\n')
+            fd.write(flake8)
+
         json_doc = validate_all()
         fd.write(json.dumps(json_doc))
     else:
-        doc_info = validate_one(func_name)
+        doc_info, doc = validate_one(func_name)
 
         fd.write(header('Docstring ({})'.format(func_name)))
         fd.write('{}\n'.format(doc_info['docstring']))
@@ -615,14 +622,40 @@ def header(title, width=80, char='#'):
             for wrn in doc_info['warnings']:
                 fd.write('\t{}\n'.format(wrn))
 
-        if not doc_info['errors']:
+        flake8 = _call_flake8_plugin(doc.source_file_name)
+        if flake8:
+            fd.write('Flake8 reported issues:\n')
+            fd.write(flake8)
+
+        if not doc_info['errors'] and not flake8:
             fd.write('Docstring for "{}" correct. :)\n'.format(func_name))
 
         if doc_info['examples_errors']:
             fd.write(header('Doctests'))
             fd.write(doc_info['examples_errors'])
 
 
+def _call_flake8_plugin(*source_file_name):
+    sub_cmds = (['flake8', '--doctest', *source_file_name],
+                ['flake8-rst', *source_file_name])
+
+    check_output = [_check_output_safe(sub_cmd) for sub_cmd in sub_cmds]
+    output = [output for output in check_output if output]
+    return '\n\n'.join(output) if output else None
+
+
+def _check_output_safe(sub_cmd):
+    try:
+        output = subprocess.check_output(sub_cmd)
+    except subprocess.CalledProcessError as e:
+        output = e.output
+    if output:
+        return '\n'.join(['Invoking command "{}" returned:'
+                         .format(' '.join(sub_cmd)), output.decode("utf-8")])
+    else:
+        return None
+
+
 if __name__ == '__main__':
     func_help = ('function or method to validate (e.g. pandas.DataFrame.head) '
                  'if not provided, all docstrings are validated and returned '