python if statement satisfied, don't continue script

Question

I am trying to get my script to print "ERROR" if a = 0. When running the script below, if I enter a as 0 I do get the message "error" but it also executes the rest of the script.

How can I get the script to only print "ERROR" if my condition is satisfied?

def print_num(a, b, c):

    if a == 0:
        print('ERROR')   

    print(a, b, c)

Use an else for the rest of your function or simply return after printing the error message. — Selcuk
– Selcuk, Commented May 21, 2020 at 5:16
To take your question literally then just replace print('ERROR') with exit('ERROR'). It is however bad practice with errors. — Mandera
– Mandera, Commented May 21, 2020 at 5:36

visibleman · Accepted Answer · 2020-05-21 05:19:19Z

4

def print_num(a, b, c):

    if a == 0:
        raise ValueError('ERROR: a must not be zero')

    print(a, b, c)

answered May 21, 2020 at 5:19

visibleman

3,3251 gold badge16 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Mandera · Accepted Answer · 2020-05-21 05:25:23Z

2

I like visibleman's solution but it would also work with an assert which is one less line and a bit cleaner

def print_num(a, b, c):
    assert a != 0

    print(a, b, c)

answered May 21, 2020 at 5:25

Mandera

3,0873 gold badges23 silver badges30 bronze badges

2 Comments

visibleman Over a year ago

For something that fits a simple test (like a==0), I think you are right, an assert is cleaner from a developer standpoint. Raising is a more general solution, and allows you to make the error a bit more descriptive to the end user.

Mandera Over a year ago

Yeah I agree, I only use raise myself. Another advantage with raising is that you can raise different errors to catch whereas assert only raises an AssertError.

Ranoiaetep · Accepted Answer · 2020-05-21 05:39:36Z

1

def print_num(a, b, c):

    if a == 0:
        print('ERROR')  
        return 

    print(a, b, c)

answered May 21, 2020 at 5:39

Ranoiaetep

6,7671 gold badge19 silver badges44 bronze badges

Comments

tanmay_garg · Accepted Answer · 2020-05-21 05:16:26Z

0

You could add an else to the code. Like so:

def print_num(a, b, c):

    if a == 0:
        print('ERROR')   
    else:
        print(a, b, c)

answered May 21, 2020 at 5:16

tanmay_garg

3971 silver badge14 bronze badges

1 Comment

medic17 Over a year ago

The OP said they want the code to halt after the error. This code will continue to run from after the if else statement.

Collectives™ on Stack Overflow

python if statement satisfied, don't continue script

4 Answers 4

Comments

2 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

2 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related