A bare-minimal script to add and remove licenses on top of python files.

license.py

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import fire

LICENSE_CONTENT = {}
LICENSE_CONTENT['apache'] = """# Copyright (C) 2018 Carnegie Mellon University. All Rights Reserved.
#
# 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.
# ==============================================================================
"""


def remove(file_path):
    """Remove existing license in the file."""
    with open(file_path) as f:
        content = f.read().splitlines()
        end_of_license_line_number = -1
        for line_number, line in enumerate(content):
            if line.startswith("#"):
                end_of_license_line_number = line_number
            else:
                break
        print("{}: end of license line number: {}".format(file_path, end_of_license_line_number))

    with open(file_path, 'w') as f:
        no_license_content = content[end_of_license_line_number + 1:]
        f.write('\n'.join(no_license_content))
        f.write('\n')


def add(file_path, license='apache'):
    """Add license to file."""
    with open(file_path, 'r+') as f:
        content = f.read()
        f.seek(0, 0)
        f.write(LICENSE_CONTENT[license] + content)


if __name__ == '__main__':
    fire.Fire()