Do you want to continue (Y/n)?

if input("Do you want to coninute? (y/N)").lower() == "y":
    run()
else:
    print("goodbye")
    exit(0)

#Entering account number
an = input("Enter your account number: ")
while not an.isdigit():
    print ("Invalid Account Number, please re-enter")
an = input("Enter your account number: ")
an = int(an)

balance = int(1500)
print ("Balance in your account is:",(balance))
print ("Choose either 1 or 2")

#To show the available options:
print ("1. Deposit")
print ("2. Withdrawal")

#Defining input and choice:
ch = input("Please enter your choice: ")
ch = int(ch)

#Choice & Calculations:
if ch == 1:
deposit = input ("Enter the amount to deposit : ")

while x:
    # do something
#this is outside of the while block

#Entering account number
input=0
an = input("Enter your account number: ")
while not an.isdigit():
    print ("Invalid Account Number, please re-enter")
an = input("Enter your account number: ")
an = int(an)

balance = int(1500)
print ("Balance in your account is:",(balance))
print ("Choose either 1 or 2")

#To show the available options:
print ("1. Deposit")
print ("2. Withdrawal")

#Defining input and choice:
ch = input("Please enter your choice: ")
ch = int(ch)

#Choice & Calculations:
if ch == 1:

if ch == 1:
    deposit = input ("Enter the amount to deposit : ")
deposit = int(deposit)
total1 = int()
total1 = (deposit + 1500)
print ("Your balance after deposit is:",(total1))

deposit = int(deposit)
total1 = int()
total1 = (deposit + 1500)
print ("Your balance after deposit is:",(total1))

if ch == 1:
    a = 9
    a += 2
    ...

print("this happens whether ch is 1 or not")

if (ch == 1) {
   do something
}

...

def main():
    print("welcome to the program")

if __name__ == '__main__':
    main()