find_ignored.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
This script takes in a single parameter representing a directory
and traverse that directory to list the exceptions that are ignored.
"""
from __future__ import print_function
import ast
import os
import sys


def find_ignored_exceptions(filename):
    # Ironically, we want to ignore code that contains errors
    try:
        with open(filename) as f:
            code = f.read()
            tree = ast.parse(code)
    except (SyntaxError, IndentationError):
        return

    for node in ast.walk(tree):
        if not isinstance(node, ast.ExceptHandler):
            continue

        nodes = list(ast.walk(node))
        if isinstance(nodes[1], ast.Pass):
            # "except:"
            yield 'Exception'
        elif (isinstance(nodes[1], ast.Name)
                and isinstance(nodes[2], ast.Pass)):
            # "except ErrorName:"
            yield nodes[1].id
        elif isinstance(nodes[1], ast.Tuple) and isinstance(nodes[2], ast.Pass):
            # "except (A, B, C):"
            for node in ast.walk(nodes[1]):
                if isinstance(node, ast.Name):
                    yield node.id
        elif (isinstance(nodes[1], ast.Name)
                and isinstance(nodes[2], ast.Name)
                and isinstance(nodes[3], ast.Pass)):
            # "except ValueError as e"
            yield nodes[1].id


if __name__ == '__main__':
    sys.argv.append('.')
    root = sys.argv[1]
    print('File Name,Exception Name')
    for dirpath, dirnames, filenames in os.walk(root):
        for filename in filenames:
            if not filename.endswith('.py'):
                continue
            full_path = os.path.abspath(os.path.join(dirpath, filename))
            for exception_name in find_ignored_exceptions(full_path):
                # print([filename, exception_name])
                print('{},{}'.format(filename, exception_name))