Script PythonFormat uses yapf to check the formatting of Python files

Scripts/PythonFormat.py

@@ -0,0 +1,69 @@
+'''
+
+Script will test the RDkit python code for conformance with the agreed format using
+yapf.
+
+For each Python file that is found in $RDBASE (excluding the build and External
+directories), yapf is used with the style configuration in $RDBASE/setup.cfg.
+If a change is required, the difference is printed. At the end of the process,
+all non-conformant files are listed and the required yapf command(s) printed.
+
+If changes are found, the script will exit with error code 1, otherwise 0.
+
+'''
+from __future__ import print_function
+import os
+from yapf.yapflib.yapf_api import FormatCode
+import sys
+
+rdbase = os.environ.get('RDBASE', '')
+styleConfig = os.path.join(rdbase, 'setup.cfg')
+
+excludeDirs = [os.path.join(rdbase, 'build'),
+               os.path.join(rdbase, 'External'), ]
+
+
+def pythonFiles(dirname=rdbase):
+  """ Find all python files below directory dirname """
+  for root, _, files in os.walk(dirname):
+    if any(root.startswith(d) for d in excludeDirs):
+      continue
+    for file in files:
+      if file.endswith(".py"):
+        yield os.path.join(root, file)
+
+
+def yapfChanges(filename):
+  """ Use yapf with the default settings to format file filename """
+  try:
+    with open(filename) as f:
+      codeBefore = f.read()
+  except UnicodeError:
+    with open(filename, encoding='latin-1') as f:
+      codeBefore = f.read()
+  try:
+    changes, changed = FormatCode(codeBefore, style_config=styleConfig, print_diff=True,
+                                  filename=filename)
+  except Exception:
+    print(filename)
+    raise
+  if changed:
+    print(changes)
+  return changed
+
+
+if __name__ == "__main__":
+  changedFiles = []
+  for s in pythonFiles():
+    if yapfChanges(s):
+      changedFiles.append(s)
+  print()
+  if changedFiles:
+    print('yapf will make changes to the following files:')
+    print('\n'.join(sorted(changedFiles)))
+    print('To apply the required changes to your code use the following command(s)')
+    for s in sorted(set(s.replace(rdbase, '').split(os.sep)[1] for s in changedFiles)):
+      print('yapf --style $RDBASE/setup.cfg --in-place --recursive $RDBASE/{0}'.format(s))
+    sys.exit(1)
+  print('Code complies with the agreed formatting rules.')
+  sys.exit(0)