The allow_abbrev option (default True) currently is documented like this (https://docs.python.org/3/library/argparse.html#allow-abbrev):> Normally, when you pass an argument list to the parse_args() method of an ArgumentParser, it recognizes abbreviations of long options.However, it also controls combinations of short options and especially the combination of flags (store_const) like `-a -b` as `-ab`.Example snippet for testing:import argparseimport sysparser = argparse.ArgumentParser(    allow_abbrev=False)parser.add_argument('-a', action='store_true')parser.add_argument('-b', action='store_true')parser.add_argument('x', nargs='*')parser.parse_args('-a -b foo bar'.split())parser.parse_args('-ab foo bar'.split())As you can see the 2nd parse will fail if allow_abbrev=False.This issue is either a doc issue only or an unintended combination of long option shortening and (the way more common) flag combinations. When i deactivated this in my code, i wanted to disable the (nice to have) long option shortening, but i unintentionally also deactivated (MUST have) short flag combinations.

Thank you for the report and for the PR. I think this is a duplicate ofissue 26967.> This issue is either a doc issue only or an unintended combination of> long option shortening and (the way more common) flag combinations.This is indeed a bug so it would be better to fix it.

ThePR 4396 should be closed.