Converts a number to an array of its constituting digits.

NumberToArrayOfDigits.py

"""
Jahus, 2015-12-13

These functions convert a number to an array containing
the digits constituting that number.

"""


def count_digits(number):
	i = 0
	while int(number / (10 ** i)) > 0:
		i += 1
	print("The number has %i digits." % i)
	return i


def number_to_array_of_digits(number):
	digits = []
	prev = 0
	count = count_digits(number)
	for j in range(count):
		k = count - (j + 1)
		red = prev * 10
		digit = int(number / (10 ** k))
		digits.append(digit - red)
		prev = digit
	return digits


def array_of_digits_to_number(number_array):
	number = 0
	count = len(number_array)
	for i in range(count):
		number += number_array[count - (i + 1)] * (10 ** i)
	return number


def start(arg):
	try:
		nbr = int(arg)
	except ValueError:
		print("Please, enter a number.")
		return
	print("Number: %s" % nbr)
	nbr_array = number_to_array_of_digits(nbr)
	nbr_sorted = nbr_array.copy()
	nbr_sorted.sort(reverse=True)
	print("Biggest number with these digits: %i" % array_of_digits_to_number(nbr_sorted))


if __name__ == "__main__":
	import sys
	_args = sys.argv
	if len(_args) != 2:
		print("Incorrect arguments.\nUse:\n\tNumToArray 1234567890")
	else:
		start(_args[1])


"""
Edited on 2018-11-12:
 * PEP8;
 * Refactored all the parts;
 * Add array_of_digits_to_number;
 * Used to find the biggest number with given digits.
"""