replace one word with another recursively

replace_all.py

#!/usr/bin/env python
# encoding: utf-8

'''
replace one word with another recursively
'''

import os
import subprocess
import os.path
import argparse
import traceback

def visitor(filepath, old_str, new_str):
    new_lines = []
    has_old_str = False
    with open(filepath, "r") as f:
        for line in f:
            if line.find(old_str) >= 0:
                has_old_str = True
                line = line.replace(old_str, new_str)
            new_lines.append(line)
    if has_old_str:
        with open(filepath, "w") as f:
            print ("repaire %s" % filepath)
            f.write(''.join(new_lines))

def is_binary(filename):
    cmd = "file -bi %s" % filename
    output = subprocess.getoutput(cmd)
    binary = False
    try:
        if output.split(";")[-1].split("=")[-1] == "binary":
            binary = True
    except Exception as e:
        pass
    return binary

def walk(root, old_str, new_str, exclude):
    for root, dirs, filenames in os.walk(root):
        if exclude:
            if exclude in dirs:
                dirs.remove(exclude)
        for filename in filenames:
            filepath = os.path.join(root, filename)
            if is_binary(filepath):
                continue
            try:
                visitor(filepath, old_str, new_str)
            except Exception as e:
                traceback.print_exc()
                print("failed on %s" % filepath)

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("-R", "--ROOT", required=True, dest="root",
            help="set root dir to scan")
    parser.add_argument("-O", "--OLD", required=True, dest="old",
            help="old string")
    parser.add_argument("-N", "--NEW", required=True, dest="new",
            help="new string")
    parser.add_argument("-E", "--EXCLUDE", dest="exclude",
            help="new string")
    args = parser.parse_args()
    root = args.root
    if not os.path.isdir(root):
        parser.print_help()
    old_str = args.old
    new_str = args.new
    exclude = args.exclude
    walk(root, old_str, new_str, exclude)

if __name__ == "__main__":
    main()