recursion clear solution for Number Length by kurosawa4434 - python coding challenges

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recursion solution in Clear category for Number Length by kurosawa4434

def number_length(a: int) -> int:
    return 1 + ((b := a // 10) and number_length(b))


if __name__ == '__main__':
    print("Example:")
    print(number_length(10))

    # These "asserts" are used for self-checking and not for an auto-testing
    assert number_length(44) == 2
    assert number_length(10) == 2
    assert number_length(0) == 1
    assert number_length(4) == 1
    print("Coding complete? Click 'Check' to earn cool rewards!")

Feb. 27, 2020

Comments:

Steapn0806 on March 27, 2020, 12:07 p.m.
python 3.8

adogadkin on March 28, 2020, 4:20 p.m.
Learned about that := operator, thanks!

vlad.bezden on July 4, 2020, 12:45 p.m.
Beautiful!

nithinchacks on March 1, 2021, 9:11 a.m.
perfect

emadharazi11_93668302487544de8 on April 12, 2021, 8:33 a.m.
Very beautiful. Got to love the use of recursion

tkachuk.constantine on April 23, 2021, 5:09 p.m.
It is beautiful solution! I spent sometime learning new python features as well as logical operators peculiarities. When then idea and process became clear, I felt quite nice felling. Thanks for sharing your art.

Eusebio_77 on June 24, 2021, 10:01 a.m.
Can anyone walk me through this?

kurosawa4434 on June 24, 2021, 11:51 a.m.
First, this solution is equivalent to the following: <pre class='brush: python'>def number_length(a: int) -> int: length = 1 while True: b = a // 10 if b > 0: length += 1 a = b else: break return length </pre>

KhantKhant on July 24, 2021, 9:11 a.m.
Wow! The code is beautiful. Please, can anyone explain me about := operator?

kurosawa4434 on July 24, 2021, 10:03 a.m.
Here is the documentation: <a href="https://docs.python.org/3/whatsnew/3.8.html">https://docs.python.org/3/whatsnew/3.8.html</a>#assignment-expressions You don't need to use this operator, but it is sometimes useful.

KhantKhant on Aug. 27, 2021, 4:25 a.m.
Thank you!

remdch on Aug. 29, 2021, 9:19 p.m.
This code is awful. Walrus operator is useless here, too much operations in one line, not human readable at all.

H0r4c3 on April 24, 2023, 5:11 p.m.
Recursion for the win!

Strings and Integers

0 %

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