Add scripting and Makefile infrastructure to create virtual envs and be ran by CI tooling.

scripts/python-lint.py

@@ -0,0 +1,139 @@
+#!/usr/bin/env python
+
+"""
+Enforces Python coding standards via pep8, pyflakes and pylint
+
+
+Installation:
+pip install pep8       - style guide
+pip install pep257     - for docstrings
+pip install pyflakes   - unused imports and variable declarations
+pip install plumbum    - used for executing shell commands
+
+This script can be called from the git pre-commit hook with a
+--git-precommit option
+"""
+
+import os
+import pep257
+import re
+import sys
+from plumbum import local, cli, commands
+
+pep8_options = [
+    '--max-line-length=105'
+]
+
+
+def lint(to_lint):
+    """
+    Run all linters against a list of files.
+
+    :param to_lint: a list of files to lint.
+
+    """
+    exit_code = 0
+    for linter, options in (('pyflakes', []), ('pep8', pep8_options)):
+        try:
+            output = local[linter](*(options + to_lint))
+        except commands.ProcessExecutionError as e:
+            output = e.stdout
+
+        if output:
+            exit_code = 1
+            print "{0} Errors:".format(linter)
+            print output
+
+    output = hacked_pep257(to_lint)
+    if output:
+        exit_code = 1
+        print "Docstring Errors:".format(linter.upper())
+        print output
+
+    sys.exit(exit_code)
+
+
+def hacked_pep257(to_lint):
+    """
+    Check for the presence of docstrings, but ignore some of the options
+    """
+    def ignore(*args, **kwargs):
+        pass
+
+    pep257.check_blank_before_after_class = ignore
+    pep257.check_blank_after_last_paragraph = ignore
+    pep257.check_blank_after_summary = ignore
+    pep257.check_ends_with_period = ignore
+    pep257.check_one_liners = ignore
+    pep257.check_imperative_mood = ignore
+
+    original_check_return_type = pep257.check_return_type
+
+    def better_check_return_type(def_docstring, context, is_script):
+        """
+        Ignore private methods
+        """
+        def_name = context.split()[1]
+        if def_name.startswith('_') and not def_name.endswith('__'):
+            original_check_return_type(def_docstring, context, is_script)
+
+    pep257.check_return_type = better_check_return_type
+
+    errors = []
+    for filename in to_lint:
+        with open(filename) as f:
+            source = f.read()
+            if source:
+                errors.extend(pep257.check_source(source, filename))
+    return '\n'.join([str(error) for error in sorted(errors)])
+
+
+class Lint(cli.Application):
+    """
+    Command line app for VmrunWrapper
+    """
+
+    DESCRIPTION = "Lints python with pep8, pep257, and pyflakes"
+
+    git = cli.Flag("--git-precommit", help="Lint only modified git files",
+                   default=False)
+
+    def main(self, *directories):
+        """
+        The actual logic that runs the linters
+        """
+        if not self.git and len(directories) == 0:
+            print ("ERROR: At least one directory must be provided (or the "
+                   "--git-precommit flag must be passed.\n")
+            self.help()
+            return
+
+        if len(directories) > 0:
+            find = local['find']
+            files = []
+            for directory in directories:
+                real = os.path.expanduser(directory)
+                if not os.path.exists(real):
+                    raise ValueError("{0} does not exist".format(directory))
+                files.extend(find(real, '-not', '-name', '._*', '-name', '*.py').strip().split('\n'))
+        else:
+            status = local['git']('status', '--porcelain', '-uno')
+            root = local['git']('rev-parse', '--show-toplevel').strip()
+
+            # get all modified or added python files
+            modified = re.findall(r"^\s[AM]\s+(\S+\.py)$", status, re.MULTILINE)
+
+            # now just get the path part, which all should be relative to the
+            # root
+            files = [os.path.join(root, line.split(' ', 1)[-1].strip())
+                     for line in modified]
+
+        if len(files) > 0:
+            print "Linting {0} python files.\n".format(len(files))
+            lint(files)
+        else:
+            print "No python files found to lint.\n"
+
+
+if __name__ == "__main__":
+    Lint.run()