Wrong answer in Python challenge?

Question

Hey! In a Python challenge, I got the question :
What is the output of this code?
a="1234 - 123"
print(a.isdecimal())

True or False

By answering False I got the wrong answer. I tried it in the following code:
https://code.sololearn.com/cm4sBY79yN1E/?ref=app
And my code output is False.

Do you know why my answer was wrong?
Thanks

Answer 1

I remember it being False. Try that question again.

Answer 2

Unfortunately it was a challenge against someone that I could win if the question wasn't wrong. Nevermind I reported the answer as wrong. Thanks for your feedback!