removeEnding.py

import argparse
import sys

from tempfile import mkstemp
from shutil import move
from os import remove, close, path

# http://code.activestate.com/recipes/577058/
def query_yes_no(question, default="yes"):
    """Ask a yes/no question via raw_input() and return their answer.

    "question" is a string that is presented to the user.
    "default" is the presumed answer if the user just hits <Enter>.
        It must be "yes" (the default), "no" or None (meaning
        an answer is required of the user).

    The "answer" return value is one of "yes" or "no".
    """
    valid = {"yes": "yes", "y": "yes", "ye": "yes", "no": "no", "n": "no"}
    if default == None:
        prompt = " [y/n] "
    elif default == "yes":
        prompt = " [Y/n] "
    elif default == "no":
        prompt = " [y/N] "
    else:
        raise ValueError("invalid default answer: '%s'" % default)

    while 1:
        sys.stdout.write(question + prompt)
        choice = input().lower()
        if default is not None and choice == "":
            return default
        elif choice in list(valid.keys()):
            return valid[choice]
        else:
            sys.stdout.write("Please respond with 'yes' or 'no' " "(or 'y' or 'n').\n")


parser = argparse.ArgumentParser(
    description="Remove lines ending with specified string in specified file"
)
parser.add_argument("filename", help="what file to delete lines from")
parser.add_argument("string", help="the string to look for at end of line")

if __name__ == "__main__":
    args = parser.parse_args()
    if not path.isfile(args.filename):
        print("Could not find the input file")
        sys.exit(1)

    print("Removing lines that end in: {0}".format(args.string))

    # first make temp file to write new file
    temp_fh, temp_abspath = mkstemp()
    temp_file = open(temp_abspath, "w")

    with open(args.filename, "r") as f:
        for line in f:
            if not line.strip().endswith(args.string):
                temp_file.write(line)

    temp_file.close()
    close(temp_fh)

    if bool(query_yes_no("Do you want us to overwrite the file?") == "yes"):
        remove(args.filename)
        move(temp_abspath, args.filename)
    else:
        newFilePath = input("Enter the new filename: ")
        while path.isfile(newFilePath):
            print("That file already exists! Try a different filename.")
            newFilePath = input("Enter the new filename: ")
        move(temp_abspath, newFilePath)