Python Forum

Hi
Sorry for that basic question, but I do not understand why the answer is always "no" when using simple quote between Y: where I'm missing something?

Thanks

Paul

MyList = ["ANSWER='Y'"]
if ("ANSWER=Y" or "ANSWER='Y'" or "ANSWER=\'Y\'") in MyList:
    print("Answer = Yes")
else:
    print("Answer = No")

Output:
Answer = No

Look at Multiple expressions with "or" keyword.

MyList = ["ANSWER='Y'"]
if MyList[0] in ("ANSWER=Y", "ANSWER='Y'", "ANSWER=\'Y\'"):
    print(f'<{MyList[0]}> is in list')

Output:
<ANSWER='Y'> is in list

Also is a little ugly that need find a string with = that has no meaning now as is just a string.

Note that non-empty strings evaluate to True when asked for their truth value.

A sequence of «or» separated items evaluates to the first «non false» item, otherwise to the last item

>>> "ANSWER=Y" or "ANSWER='Y'" or "ANSWER=\'Y\'"
'ANSWER=Y'
>>> 

Similarly a sequence of «and» seperated items evaluates to the first «false» item, otherwise to the last item.

Ok I figured out my mistake
Thanks

(May-02-2022, 10:17 AM)paul18fr Wrote: [ -> ]Hi
Sorry for that basic question, but I do not understand why the answer is always "no" when using simple quote between Y: where I'm missing something?

Thanks

Paul

What are you trying to do? This seems an odd construct.

Is this closer to what you want (just guessing)

MyList = ["Y", "y"]
if answer in MyList:
    print("Answer = Yes")
else:
    print("Answer = No")

I've been using such kind of snippet in conjunction with "sys.argv"; as mentioned in previous post, my code was wrong, and I modified it. Now it works as expected.

Thanks to all

MyList = ["ANSWER='Y'"]
if ("ANSWER=Y" in MyList) or ("ANSWER='Y'" in MyList):
    print("Answer = Yes")
else:
    print("Answer = No")

You could use ArgumentParser, which returns a Namespace, where you can access for example to answer.

from argparse import ArgumentParser


ANSWERS = ("n", "y")


def get_args():
    parser = ArgumentParser()
    parser.add_argument("--answer", dest="ANSWER", metavar="YOUR_CHOICE", default="n", choices=ANSWERS)
    return parser.parse_args()


if __name__ == "__main__":
    print(get_args())

I named the script c.py:

Quote:[andre@andre-Fujitsu-i5 ~]$ python c.py -h
usage: c.py [-h] [--answer YOUR_CHOICE]

options:
-h, --help show this help message and exit
--answer YOUR_CHOICE
[andre@andre-Fujitsu-i5 ~]$ python c.py --answer y
Namespace(ANSWER='y')
[andre@andre-Fujitsu-i5 ~]$ python c.py --answer i
usage: c.py [-h] [--answer YOUR_CHOICE]
c.py: error: argument --answer: invalid choice: 'i' (choose from 'y', 'n')

Also, arguments with more than one parameter (nargs) are possible.