Message274725
https://docs.python.org/3/howto/argparse.html#combining-positional-and-optional-arguments
"And, just like the “store_true” action, if you don’t specify the -v flag, that flag is considered to have None value."
This sentence is misleading. It supposes that "store_true" action can save None value. But "store_true" action always saves True or False value.
An example:
This code was taken from the argparse howto. I've just added the -f option and printed args to the stdout.
a.py
#!/usr/bin/env python3
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display the square of a given number")
parser.add_argument("-v", "--verbosity", action="count",
help="increase output verbosity")
parser.add_argument("-f", "--flag", action="store_true")
args = parser.parse_args()
print('args:', args)
The output in the console:
[guest@localhost bugs]$ ./a.py 1
args: Namespace(flag=False, square=1, verbosity=None)
[guest@localhost bugs]$
In the output we see that the -f option have got the False value not None.
Applied a patch to the issue that just removes words about analogy with store_true action. |
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Date |
User |
Action |
Args |
2016-09-07 03:04:18 | py.user | set | recipients:
+ py.user, docs@python |
2016-09-07 03:04:18 | py.user | set | messageid: <1473217458.1.0.785896151958.issue27991@psf.upfronthosting.co.za> |
2016-09-07 03:04:18 | py.user | link | issue27991 messages |
2016-09-07 03:04:17 | py.user | create | |
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