How to Check for no input in Python

Question

# Imports
import re

# Variables
contestants = []


def run(string):
    incorrectSymbols = re.compile('[@_!#$%^&*()<>?/\|}{~:]')
    if (incorrectSymbols.search(string) == None):
        return "yes"
    else:
        return "no"


def bootUp():
    print(""">>> Hello judges!
>>> Today you will be viewing 6 contestants!
>>> To continue please enter all contestants names!""")
    contestantNames()


def contestantNames():
    for i in range(0, 6):
        while True:
            x = input(">>> Contestant number " + str(i) + " name: ")
            if run(x) == "yes":
                break
            elif run(x) == "no":
                print(">>> No symbols allowed!")
            elif x=="":            # Here is what im confused about.
                print(">>> You can't leave it blank!")
            else:
                print(">>> Error in run function.")
    contestants.append(x)
    print(contestants)


bootUp()

After reading up on this problem I found multiple accounts saying to do this simply use (variable)="" . However, this does not work for me, any other ideas?

My code is an attempt for a dance project where contestants all take turns and each judge scores each contestant. A tournament to be put simply. This part of the code would be the beginning where I obtain the contestant's names and i need to make sure they have no symbols or left blank.

Poojan · Accepted Answer · 2020-02-17 21:32:51Z

4

Somehow it looks like your run is not working as you expected. Its returning 'yes' and 'no' not True and False. Ordering of your if else is wrong you need to fix that.
just move up if x=='' condition and it will work.

# Imports
import re

# Variables
contestants = []


def run(string):
    incorrectSymbols = re.compile('[@_!#$%^&*()<>?/\|}{~:]')
    if (incorrectSymbols.search(string) == None):
        return "yes"
    else:
        return "no"


def bootUp():
    print(""">>> Hello judges!
>>> Today you will be viewing 6 contestants!
>>> To continue please enter all contestants names!""")
    contestantNames()


def contestantNames():
    for i in range(0, 6):
        while True:
            x = input(">>> Contestant number " + str(i) + " name: ")
            if x == "":            # Here is what im confused about.
                print(">>> You can't leave it blank!")
            elif run(x) == "yes":
                break
            elif run(x) == "no":
                print(">>> No symbols allowed!")
            else:
                print(">>> Error in run function.")
    contestants.append(x)
    print(contestants)


bootUp()

Another solution is to change run function like this.

def run(string):
    if string == "":
        return
    incorrectSymbols = re.compile('[@_!#$%^&*()<>?/\|}{~:]')
    if (incorrectSymbols.search(string) == None):
        return "yes"
    else:
        return "no"

This will work with your default if else ordering.

edited Feb 17, 2020 at 21:32

answered Nov 20, 2019 at 21:33

Poojan

3,5372 gold badges20 silver badges36 bronze badges

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

1 Comment

Coder Cody Over a year ago

rookie mistake x)

Collectives™ on Stack Overflow

How to Check for no input in Python

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related