Iterate over all files in directory and add a line between the 1st and the 2nd

Add line to all files in directory

Naming file

run.py

#!/usr/bin/env python3

import os


newline = "hello world\n"


def fix(path):
    print(path)
    with open(path, 'r') as f:
        lines = f.readlines()
        lines = lines[:1] + [newline] + lines[1:]
    with open(path, 'w') as f:
        f.writelines(lines)


root = '.'
for dir, _, files in os.walk(root):
    for fname in files:
        path = '%s/%s' % (dir, fname)
        fix(path)