how do you break code in a if loop? - python-3.3

Question

okay two questions my instructor wants me to break my code after my else statement because the menu() function keeps repeating itself after "customer not found" but I don't understand what she means also for some reason my code only runs using only the first name in the "customers" list instead of all the names if anybody could point out the flaws in my code that would be great thank you.
#Program 3 BankApp
def customerind(customer):
ind = ""
for i in range(len(customers)):
if customer == customers[i]:
ind = i
if ind != "":
return ind
else:
print("customer not found")
def printbalance(index):
print("your remaining balance is", balances[index])
def menu():
print("type D to deposit money", customer)
print("type W to withdraw money", customer)
print("type B to display balance", customer)
print("type C to change user", customer)
print("type E to exit", customer)
def withdraw(index, withdrawAmt):
if withdrawAmt < balances[index]:
balances[index] = balances[index] - withdrawAmt
else:
print("you went over your balance")
def deposit(index, depositAmt):
balances[index] = balances[index] + depositAmt
global customers
customers= ["Mike", "Jane", "Steve"]
global balances
balances= [300, 300, 300]
global index
customer= input("what is your name?")
index= customerind(customer)
printbalance(index)
answer= ""
while answer != "E":
menu()
answer= input("what is your menu choice?")
if answer=="C":
customer= input("who are you?")
index= customerind(customer)
if answer== "W":
withdrawAmt = float(input("how much did you want to withdraw today?"))
withdraw(index, withdrawAmt)
printbalance(index)
if answer=="B":
printbalance(index)
if answer=="D":
depositAmt = float(input("how much did you want to deposit today?"))
deposit(index, depositAmt)
printbalance(index)

Answer 1

You have a few issues here.
1. "for some reason my code only runs using only the first name in the "customers" list"
In your customerind function, you are printing "customer not found" after only the first iteration. You need to move the else statement outside of the for loop so that it can iterate through all of the names.
def customerind(customer):
#Iterate through each name, and see if there is a match.
for i in range(len(customers)):
if customer == customers[i]:
return i #If we found the name, instantly return the index.
#Outside of the for loop, will get called once above finishes iterating through all names.
return -1 #Return -1 if no match, since the index can be any value 0 -> Infinity
So the way this function works now, is that if the name is found in the for loop, then it returns the index. If the name is not found after iterating through all of the names, then the function will return -1.
Now that this function is setup a bit better, let's look at your main code at the bottom...
menu() is constantly being called so long as the user does not type E. So then if you want to automatically exit if the customer is not found, you should do something like this:
answer= ""
while answer != "E":
menu()
answer= input("what is your menu choice?")
if answer=="C":
customer= input("who are you?")
index= customerind(customer)
if index == -1:
print('Customer not found. Exiting...')
break #Break out of the while loop above so the program exits.
if answer== "W":
withdrawAmt = float(input("how much did you want to withdraw today?"))
withdraw(index, withdrawAmt)
printbalance(index)
if answer=="B":
printbalance(index)
if answer=="D":
depositAmt = float(input("how much did you want to deposit today?"))
deposit(index, depositAmt)
printbalance(index)