Why this Python Program is not printing remaining armstrong number till 10000? It is only printing up to 407

I am new to python and below is my code it is printing only 1, 153, 370, 371 and 407.

def checkArmStrong(num):
    sum = 0
    temp = num
    while temp > 0:
        rem = temp % 10
        sum += rem ** 3
        temp //= 10
    return sum == num


for x in range(1, 10000):
    if checkArmStrong(x):
        print(x)

>Solution :

You need to adjust the power in your calculation, right now it’s always 3, which works for three-digit numbers but is not correct for numbers with more/less digits.

An Armstrong number is a number that equals the sum of its digits, each raised to the power of the number of digits. So for a 2 digit number the power needs to be 2, then 3 for a 3 digit number and so on.

You can fix your calculation like this:

def checkArmStrong(num):
    sum = 0
    temp = num
    num_digits = len(str(num))
    while temp > 0:
        rem = temp % 10
        sum += rem ** num_digits
        temp //= 10
    return sum == num