added pep8 git pre commit hook

Readme.md

@@ -1,16 +1,22 @@
-#Boilerplate Collection
+# Boilerplate Collection
 
 Boilerplates are basic setups with best practices. Just take the parts you like.
 
-###Python
+### Python
 
 * [Python Script](https://github.com/metachris/boilerplates/tree/master/python)
 * [Tornado Website](https://github.com/metachris/tornado-boilerplate)
 * [App Engine Website](https://github.com/metachris/appengine-boilerplate)
 
 
-###Dotfiles
+### PEP8 Pre Commit Hook for Git
+
+This [git pre-commit hook](https://github.com/metachris/boilerplates/tree/master/python/pep8-git-pre-commit-hook) checks for pep8 compatibility on committing, and aborts the commit if errors are found. Can be skipped by applying the `--no-verify` flag to `git commit`. This requires the tool `pep8` which can be installed via package managers and homebrew.
+
+To use the commit hook in all projects on this system, copy it into the global git hook-templates directory (eg. `/usr/share/git-core/templates/hooks/`) as a file called `pre-commit` and set the permissions to executable. Afterwards you can enable this hook in existing repositories by calling `git init`. New repositories will use it by default.
 
-[Boilerplate dotfiles](https://github.com/metachris/boilerplates/tree/master/dotfiles) is a collection of command line goodness for OSX and Linux. Includes `.bash_profile`, `.aliases`, `.exports`, and others.
 
+### Dotfiles
+
+[Boilerplate dotfiles](https://github.com/metachris/boilerplates/tree/master/dotfiles) is a collection of command line goodness for OSX and Linux. Includes `.bash_profile`, `.aliases`, `.exports`, and others.
 

python/pep8-git-pre-commit-hook

@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+from __future__ import with_statement
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def system(*args, **kwargs):
+    kwargs.setdefault('stdout', subprocess.PIPE)
+    proc = subprocess.Popen(args, **kwargs)
+    out, err = proc.communicate()
+    return out
+
+
+def main():
+    files = (file for file in system('git', 'diff', '--name-only', '--staged', '--diff-filter=AM').splitlines() if file.endswith('.py'))
+
+    tempdir = tempfile.mkdtemp()
+    for name in files:
+        filename = os.path.join(tempdir, name)
+        filepath = os.path.dirname(filename)
+        if not os.path.exists(filepath):
+            os.makedirs(filepath)
+        with file(filename, 'w') as f:
+            system('git', 'show', ':' + name, stdout=f)
+    output = system('pep8', '.', cwd=tempdir)
+    shutil.rmtree(tempdir)
+    if output:
+        print output,
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main()