String comparison, less than sign

Question

I have two strings, Right and banana. When I compare, Right < banana the result is given as True. I understand that Python compares letter by letter.

(1) But then these two strings are not in the same length. How would this be possible? (2) I looked up the ASCII, then I tried the following: R < b, and the result is True; i < a, and the result is False, and so on. Clearly we have False and True in comparing letter by letter, Right < banana. How does Python determine that the final result is True?

I did look up a few sources online, and couldn't find answer. I've just started to learn Python as my first programming language, so maybe I didn't know where to look...

http://stackoverflow.com/questions/4806911/string-comparison-technique-used-by-python — dfrib, Jan 10 '16 at 20:38
The search term you're looking for is "lexicographical ordering". — Mark Dickinson, Jan 10 '16 at 20:40

score 5 · Answer 1 · answered Jan 10 '16 at 20:37

5

Python compares sequences naively. Since "R" is less than "b", "Right" is less than "banana".

answered Jan 10 '16 at 20:37

Ignacio Vazquez-Abrams

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In the ascii table, you first have all uppercase letters, then all lowercase letters. So r > b, but R < b. – Bartez Jan 10 '16 at 20:49

score 0 · Answer 2 · answered Jan 10 '16 at 20:51

0

Python uses the ASCII/Byte/Unicode point value to compare chars For example

def python_less_than(s1, s2):
    'a function that acts like the way python compare strings'
    return [ord(c) for c in s1] < [ord(c) for c in s2]

answered Jan 10 '16 at 20:51

Yoav Glazner

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String comparison, less than sign

2 Answers2