sum_of_digits.py

defsum_of_digits(n: int) ->int:
"""
 Find the sum of digits of a number.
 >>> sum_of_digits(12345)
 15
 >>> sum_of_digits(123)
 6
 >>> sum_of_digits(-123)
 6
 >>> sum_of_digits(0)
 0
 """
n=abs(n)
res=0
whilen>0:
res+=n%10
n//=10
returnres


defsum_of_digits_recursion(n: int) ->int:
"""
 Find the sum of digits of a number using recursion
 >>> sum_of_digits_recursion(12345)
 15
 >>> sum_of_digits_recursion(123)
 6
 >>> sum_of_digits_recursion(-123)
 6
 >>> sum_of_digits_recursion(0)
 0
 """
n=abs(n)
returnnifn<10elsen%10+sum_of_digits(n//10)


defsum_of_digits_compact(n: int) ->int:
"""
 Find the sum of digits of a number
 >>> sum_of_digits_compact(12345)
 15
 >>> sum_of_digits_compact(123)
 6
 >>> sum_of_digits_compact(-123)
 6
 >>> sum_of_digits_compact(0)
 0
 """
returnsum(int(c) forcinstr(abs(n)))


defbenchmark() ->None:
"""
 Benchmark multiple functions, with three different length int values.
 """
fromcollections.abcimportCallable
fromtimeitimporttimeit

defbenchmark_a_function(func: Callable, value: int) ->None:
call=f"{func.__name__}({value})"
timing=timeit(f"__main__.{call}", setup="import __main__")
print(f"{call:56} = {func(value)} -- {timing:.4f} seconds")

forvaluein (262144, 1125899906842624, 1267650600228229401496703205376):
forfuncin (sum_of_digits, sum_of_digits_recursion, sum_of_digits_compact):
benchmark_a_function(func, value)
print()


if__name__=="__main__":
importdoctest

doctest.testmod()
benchmark()