Python: Values don't get returned from function

Question

I had this code that iterates through users input and returns the output

while True:
 city = input("Enter city.")
 if city in city_list:
 print (city,'selected')
 break
 else:
 print ('Please try again.')

As I am asking several times for input, it looked redundant, I tried to capsulate it in one function, here is the entire function

def get_filters():
 print ('Welcome .')
 #list for month and day data_user
 city_list=['city1','city2','city3']
 month_list=['January', 'February', 'March', 'April', 'May','June','All']
 day_list=['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday','All']
 city_string=('Enter city.')
 city=None
 month_string=('Enter month.')
 month=None
 day_string=('Enter day.')
 day=None
 def check_input(data, s_string, data_list):
 while True:
 data = input(s_string)
 if data in data_list:
 print (data,'selected')
 return data
 break
 else:
 print ('Please try again.')
 check_input(city, city_string, city_list)
 check_input(month, month_string, month_list)
 check_input(day, day_string, day_list)
 return city, month, day

If I run the code I get an error message that later in the code the values can't be loaded.city, day and month are not getting passed. Is there something wrong in how I return the values?

• pstatix: Your indentation is off here, please fix that as well as post the entire error you receive.
• Jean Rostan: You do not save the value reported by your check_input: you need to do: city = check_input(city,city_string,city_list). Your city inside check_input is not in the scope of your higher function, so for the higher function, city is still at None

Answer 1

Not sure what is your intent here, assuming you want to capture the three choices entered by the user. Here is a working code under python3. Please try this...

#!/usr/local/Cellar/python/3.6.5/bin/python3
def get_filters():
 print ('Welcome .')
#list for month and day data_user
city_list=['city1','city2','city3']
month_list=['January', 'February', 'March', 'April', 'May','June','All']
day_list=['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday','All']
city_string=('Enter city.')
city=None
month_string=('Enter month.')
month=None
day_string=('Enter day.')
day=None
def check_input(data, s_string, data_list):
 while True:
 data = input(s_string)
 if data in data_list:
 print (data)
 return data
 break
 else:
 print ('Please try again.')
selection = (check_input(city, city_string, city_list) , check_input(month, month_string, month_list) , check_input(day, day_string, day_list))
print (selection)
---Output--- 
 Enter city.city1
 city1
 Enter month.January
 January
 Enter day.Monday
 Monday
 ('city1', 'January', 'Monday')