Typeerror: unbound method f() must be called with validity instance as first argument (got type instance instead)

Question

0.00/5 (No votes)

See more:

I need to make a program that will ask user to enter a string of parenthesis, validate the order of parenthesis (must be close to '(,),{,},[,],(),{},[]' as valid and '(},{{{,{][[)' as invalid) and give an error message if the user entered a non-parenthesis character.

I haven't done the error message code but I got this
TypeError: unbound method f() must be called with validity instance as first argument (got type instance instead)

What I have tried:

class validity: def f(str): a= ['()', '{}', '[]'] while any(i in str for i in a): for j in a: str = str.replace(j, '') return not str while True: s = input("Enter parentheses : ") print(s, "-", "is Valid" if validity.f(s) else "is Invalid")

What should I do to correct it?

Posted 11-Jan-21 21:15pm

lil_mint

Updated 11-Jan-21 23:01pm

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard MacCutchan · Accepted Answer · 2021-01-11T23:01:00

You need to create an instance of the validity class, and use that instance to call the function. Something like:

Python

v = validity() # create a validity instance
while True:
     s = input("Enter parentheses : ")
     print(s, "-", "is Valid" 
           if v.f(s) else "is Invalid") # use the instance v to call the function f

See 9. Classes — Python 3.7.9 documentation[^].