Apply the Apache License to a set of Go files

applylicense.py

import glob
import pprint

HEADER = """
/*
	Copyright [yyyy] [name of copyright owner]
  
	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

		http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
*/
"""

files = glob.glob("**/*.go", recursive=True)
for filename in files:
    with open(filename) as f:
        contents = f.readlines()
    header_location = contents[1:len(HEADER.split("\n"))]
    if ''.join(header_location) == HEADER:
        print(f"skipping {filename}")
        continue
    contents.insert(1, HEADER)
    with open(filename, 'w') as f:
        f.write(''.join(contents))