Sentinel Loops¶

In [1]:
def main():
_sum= 0.0
count = 0
x = float(input("Enter a number (negative to quit) >> "))
while x >= 0:
_sum += x
count += 1
x = float(input("Enter a number (negative to quit) >> "))
print("\nThe average of the numbers is {0:0.2f}".format(_sum/count))

In [2]:
main()

Enter a number (negative to quit) >> 3
Enter a number (negative to quit) >> 345
Enter a number (negative to quit) >> 23
Enter a number (negative to quit) >> 7
Enter a number (negative to quit) >> 23
Enter a number (negative to quit) >> -1

The average of the numbers is 80.20

In [3]:
def main2():
_sum= 0.0
count = 0
x_str = input("Enter a number (press enter to quit) >> ")
while x_str != "":
x = float(x_str)
_sum += x
count += 1
x_str = input("Enter a number (press enter to quit) >> ")
print("\nThe average of the numbers is {0:0.2f}".format(_sum/count))

In [4]:
main2()

Enter a number (press enter to quit) >> 34
Enter a number (press enter to quit) >> 456
Enter a number (press enter to quit) >> -23
Enter a number (press enter to quit) >> 245
Enter a number (press enter to quit) >> -536
Enter a number (press enter to quit) >> -23
Enter a number (press enter to quit) >>

The average of the numbers is 25.50