How do you use a loop for a function?

Question

I have written most of the codes already, but I am still having a hard time figuring out the code to loop the program (for a function) as many times the user desires until the user is done. Also, I am unable to use a For loop.

def load():
 a=input("Name of the stock: ")
 b=int(input("Number of shares Joe bought: "))
 c=float(input("Stock purchase price: $"))
 d=float(input("Stock selling price: $"))
 e=float(input("Broker commission: "))
 return a,b,c,d,e

def calc(b,c,d,e):
 w=b*c
 x=c*(e/100)
 y=b*d
 z=d*(e/100)
 pl=(x+z)-(y-z)
 return w,x,y,z,pl

def output(a,w,x,y,z,pl):
 print("The Name of the Stock: ",a)
 print("The amount of money Joe paid for the stock: $",format(w,'.2f'))
 print("The amount of commission Joe paid his broker when he bought the stock: $",format(x,'.2f'))
 print("The amount that Jim sold the stock for: $",format(y,'.2f'))
 print("The amount of commission Joe paid his broker when he sold the stock: $",format(z,'.2f'))
 print("The amount of money made or lost: $",format(pl,'.2f'))

def main():
 a,b,c,d,e=load()
 w,x,y,z,pl=calc(b,c,d,e)
 output(a,w,x,y,z,pl)

main()

For what you want, you need to use a `while()` loop. The condition should be some flag that when you set an EOF from the user, the loop will stop too. — Avihoo Mamka, Mar 06 '16 at 10:04
@AvihooMamka Would I be putting the while() in the def main() or somewhere else? — Gangaji, Mar 06 '16 at 10:09
Wherever you wrap your function that needs to be running multiple times. — Avihoo Mamka, Mar 06 '16 at 10:10

score 0 · Answer 1 · answered Mar 06 '16 at 10:13

Calling a function in a loop is fairly simple, you wrap in either in a while or a for loop and call it inside. The below code executes the brookerage function 10 times. I suppose you can use this as an example and customize the entire thing for your needs.

def brookerage():
 a,b,c,d,e=load()
 w,x,y,z,pl=calc(b,c,d,e)
 output(a,w,x,y,z,pl)

def main():
 for i in range(0,10):
  brookerage()

main()

score 0 · Accepted Answer · edited May 23 '17 at 12:15

To let the user decide if they want to keep looping and not any fixed number of times, ask the user:

# in place of the call to main() above, put:
while input('Proceed? ') == 'y':
  main()

So it keeps looping over main() as long as the user enters 'y'. You can change it to 'yes', 'Yes', etc. as needed.

Side note:
1. You should use more than 1 space for indent. Typically 4 spaces, or at least 2.
2. read up on if __name__ == "__main__".

How do you use a loop for a function?

2 Answers2