New submission from py.user: https://docs.python.org/3/library/argparse.html#argumentparser-objects "prog - The name of the program (default: sys.argv[0])" It doesn't take all sys.argv[0]. It splits sys.argv[0] and takes only the trailing part. An example: a.py #!/usr/bin/env python3 import argparse import sys parser = argparse.ArgumentParser() parser.add_argument("arg", help="The name is %(prog)s, the sys.argv[0] is " + sys.argv[0]) args = parser.parse_args() The output in the console: [guest@localhost bugs]$ ../bugs/a.py -h usage: a.py [-h] arg positional arguments: arg The name is a.py and sys.argv[0] is ../bugs/a.py optional arguments: -h, --help show this help message and exit [guest@localhost bugs]$ In the output we see that %(prog)s takes only trailing part of sys.argv[0] not all. Applied a patch to the issue that specifies about part of sys.argv[0]. ---------- assignee: docs@python components: Documentation, Library (Lib) files: argparse_sys-argv-0-part.diff keywords: patch messages: 274729 nosy: docs@python, py.user priority: normal severity: normal status: open title: In the argparse there is a misleading words about %(prog)s value type: behavior versions: Python 3.6 Added file: http://bugs.python.org/file44420/argparse_sys-argv-0-part.diff _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue27992> _______________________________________