Search python files for division operators, helping spot issues with python3 migrations

divide.py

#!/usr/bin/env python
"""
This script will search python files inside directories and list use of
the division operator.

It is meant to help spot possible issues with python3 migrations

"""
import io
import os
import ast
import sys
import itertools


def search_file(filename):
    data = io.open(filename, mode='rb').read()
    try:
        parsed = ast.parse(data, filename)
    except SyntaxError as err:
        print('ERROR', filename, err)
        return

    lines = data.decode().splitlines()
    prev = None
    for node in ast.walk(parsed):
        if isinstance(node, ast.Div):
            yield filename, node, prev, lines[prev.lineno - 1]
        prev = node


def gather(dirs):
    for directory in dirs:
        for root, _, files in os.walk(directory):
            for file in files:
                if file.endswith('.py'):
                    yield os.path.join(root, file)


def main():
    dirs = sys.argv[1:]

    print('Searching for division operator in %s' % (', '.join(dirs)))
    files = gather(dirs)

    res = itertools.chain(*map(search_file, files))

    for filename, node, prev, line in res:
        print('%s:%d  %s' % (filename, prev.lineno, line.strip()))


if __name__ == '__main__':
    main()