parser. parse_ Args boolean type resolves false to true

Record a big pit , Many times , Never had a long memory ==！

problem

When I use parser When adding a parameter , Set it to bool Type of , Then the default value is True.

parser.add_argument("--some_argument", default=True, type=bool)

However , When I type --some_argument=False When , The code comes out some_argument This parameter is still True.

I suspect that my coding posture is wrong , Changed --some_argument=false（ A lowercase letter ） --some_argument=0 etc. , When the result code runs some_arguemnt Still True value .

reason

On the command line , Input false, perhaps “0” perhaps “False”, Are parsed into strings , After the string is converted to boolean type, it is like this ：

>>> bool("false")
True
>>> bool("False")
True
>>> bool("0")
True

So no matter what we type in the command line , The code parses out True.

Solution

1. Simple and effective , From now on, do not set the default value to True Parameters of , Only set the default value to False Parameters of . In general, he defaults to False, If necessary, change the value of this parameter to True, You only need to enter this parameter on the command line =True That's it , In this way, the parameter will be resolved to True.

parser.add_argument("--some_argument", default=False, type=bool)

2. The second is to use “store_true” This setting , The default effect is basically the same as the above

parser.add_argument("--some_argument", action="store_true")

If you want this parameter to be True, Enter... On the command line --some_argument, If it is not entered, the default is False.