python -- how to prevent the first iteration and the second iteration to have same value on a same variable

Question

i have this function below

def looping_steps():
print('**** Checking Balance ********')
while True:
balance = 20
if balance > 0:
tbs = balance * 0.9
break
print('repeat again and again')

# if its balance bigger then zero
print('do something ' )

while True:
looping_steps()

i want the second iteration of while loop if it equal 20 for example i want to change tbs formula for example tbs = balance * 0.8 how can i acheive

Answer 1

i would like to give an example and you know getting balance is dynamic it will be the first iteration 10 and i want to avoid the second iteration to become 10 again if it's become i want to change the formula

Answer 2

Haji Abdirahim Ali ,

If you want a function to remember variable values between calls (and the changes you make to them), make it a generator by using yield instead of return (your function currently uses neither). Generators are taught in Python Intermediate.

Don't hard code 20 inside the while loop, or it will reset to 20 each iteration.

Answer 3

Haji Abdirahim Ali ,

There's an indentation error in the line containing not.

I want to help you clean up this part:

while True:
balance = 20
if balance > 1:
if use_alternative_formula:
tbs = balance * 0.95
else:
tbs = balance * 0.92
break
print('repeat again and again')

You have while True: but it only executes once because you always break, so that can be removed.

You set balance to 20 and immediately check if balance > 1, which is always True, so you don't need that either.

Because you always break, print('repeat again and again') is never reached, so you don't need that either.

And without while, we don't need break.

This shorter code would produce the same behavior:

balance = 20
if use_alternative_formula:
tbs = balance * 0.95
else:
tbs = balance * 0.92

Answer 4

Haji Abdirahim Ali ,

If you don't know generators yet, you can make a function use different values by sending those values as arguments and changing the values at the call site rather than in the function.

def add_tax(price, tax):
return price * tax

tax = 1.0
for price in range(10, 40, 10):
tax += 0.04
print(price, tax, add_tax(price, tax))

""" Output:
10 1.04 10.4
20 1.08 21.6
30 1.12 33.6
"""

Answer 5

@rain

i got it the point, what i was need is Boolean to determine every iteration

i use

use_alternative_formula = False
def looping_steps():
print('**** Checking Balance ********')
global use_alternative_formula
while True:
balance = 20

if balance > 1:
if use_alternative_formula:
tbs = balance * 0.95
else:
tbs = balance * 0.92
break
print('repeat again and again')

# if its balance bigger then zero
print('do something ' )
# update the boolean flag to true / false
use_alternative_formula = not use_alternative_formula

while True:
looping_steps()