Create a while loop that gets input from user and checks for negative values

Question

I am trying to create a simple while loop that checks whether any of three values are negative, and if True, asks for those three values again.

Here is my code:

def vyohykeliput(): rivi = input("How many AB-zone trips do you make per month?\n") ABmatka = int(rivi) rivi1 = input("How many BC-zone trips do you make per month?\n") BCmatka = int(rivi1) rivi2 = input("How many ABC-zone trips do you make per month?\n") ABCmatka = int(rivi2) while ABmatka or BCmatka or ABCmatka < 0: print("The given values cannot be negative!") rivi = input("How many AB-zone trips do you make per month?\n") ABmatka = int(rivi) rivi1 = input("How many BC-zone trips do you make per month?\n") BCmatka = int(rivi1) rivi2 = input("How many ABC-zone trips do you make per month?\n") ABCmatka = int(rivi2) vyohykeliput()

But all I managed to get as output is printing "The given values..." each time I run the program, whether the given numbers are negative or not. Also, I've managed to make it print "The given values..." an infinite number of times.

Your while condition is interpreted as while ABmatkla is True or BCmatka is True or ABCmatkca is lesser than 0 in python a non empty string is considered True and any non 0 integer as well. This means that ABmatkla, BCmatka are always evaluated as True. Just add < 0 to all variables in the condition should make it work — Plopp
– Plopp, Commented Sep 25, 2019 at 11:43

user2390182 · Accepted Answer · 2019-09-25 11:44:53Z

What you want to do is:

while ABmatka < 0 or BCmatka < 0 or ABCmatka < 0: # ...

A short-hand (at least for more values or an iterable of values) for that would be

while any(x < 0 for x in (ABmatka, BCmatka, ABCmatka)): # ...

ABmatka or BCmatka or ABCmatka < 0 is truthy if either of the following expressions is truthy:

ABmatka BCmatka ABCmatka < 0

lander15 · Accepted Answer · 2019-09-26 08:32:23Z

Put like this:

while ABmatka < 0 or BCmatka < 0 or ABCmatka < 0:

If you only put like this you are asking if ABmatka or BCmatka are not None or any other falsy value like 0, "", [],

while ABmatka or BCmatka or ABCmatka < 0:

Collectives™ on Stack Overflow

Create a while loop that gets input from user and checks for negative values

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related