bpo-23596: Use argparse for the command line of gzip

Co-authored-by: Antony Lee <anntzer.lee@gmail.com>

Author: matrixise

Lib/gzip.py

@@ -532,18 +532,17 @@ def decompress(data):
  return f.read()
 
 
-def _test():
- # Act like gzip; with -d, act like gunzip.
- # The input file is not deleted, however, nor are any other gzip
- # options or features supported.
- args = sys.argv[1:]
- decompress = args and args[0] == "-d"
- if decompress:
- args = args[1:]
- if not args:
- args = ["-"]
- for arg in args:
- if decompress:
+def main():
+ from argparse import ArgumentParser
+ parser = ArgumentParser(description=
+ "A simple command line interface for the gzip module: act like gzip, "
+ "but do not delete the input file.")
+ parser.add_argument("-d", "--decompress", action="store_true",
+ help="act like gunzip instead of gzip")
+ parser.add_argument("args", nargs="*", default=["-"])
+ args = parser.parse_args()
+ for arg in args.args:
+ if args.decompress:
  if arg == "-":
  f = GzipFile(filename="", mode="rb", fileobj=sys.stdin.buffer)
  g = sys.stdout.buffer
@@ -571,4 +570,4 @@ def _test():
  f.close()
 
 if __name__ == '__main__':
- _test()
+ main()