Print all Armstrong Numbers in Python

Enter lower bound: 100
Enter upper bound: 9999
153, 370, 371, 407, 1634, 8208, 9474,

from math import floor, log


def main():
	"""
	Prints all the Armstrong numbers within a given range.
	"""

	# Get the lower and upper bounds
	a = int(input("Enter lower bound: "))
	b = int(input("Enter upper bound: "))

	# Print all the Armstrong numbers
	for i in range(a, b + 1):
		if is_armstrong(i):
			print(i, end=", ")
	print()


def is_armstrong(number: int):
	"""
	Checks if a number is an Armstrong number or not.
	"""

	# Check if the number is positive
	if number < 0:
		return False

	BASE = 10

	# Find the total number of digits
	count = number_length(number, BASE)

	# Calculate the sum of the digits
	total = 0
	n = number
	while n != 0:
		unit_digit = n % BASE
		total += unit_digit**count
		n //= BASE

	return total == number


def number_length(number: int, base: int):
	"""
	Returns the number of digits in a number.
	"""

	number = abs(number)
	return floor(log(number, base)) + 1 if number != 0 else 1


if __name__ == "__main__":
	main()