mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-27 23:11:09 +00:00
7f94a73eec
* First commit camel case to snake case conversion algorithm, including numbers * code modified to not use regex
61 lines
1.6 KiB
Python
61 lines
1.6 KiB
Python
def camel_to_snake_case(input_str: str) -> str:
|
|
"""
|
|
Transforms a camelCase (or PascalCase) string to snake_case
|
|
|
|
>>> camel_to_snake_case("someRandomString")
|
|
'some_random_string'
|
|
|
|
>>> camel_to_snake_case("SomeRandomStr#ng")
|
|
'some_random_str_ng'
|
|
|
|
>>> camel_to_snake_case("123someRandom123String123")
|
|
'123_some_random_123_string_123'
|
|
|
|
>>> camel_to_snake_case("123SomeRandom123String123")
|
|
'123_some_random_123_string_123'
|
|
|
|
>>> camel_to_snake_case(123)
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: Expected string as input, found <class 'int'>
|
|
|
|
"""
|
|
|
|
# check for invalid input type
|
|
if not isinstance(input_str, str):
|
|
msg = f"Expected string as input, found {type(input_str)}"
|
|
raise ValueError(msg)
|
|
|
|
snake_str = ""
|
|
|
|
for index, char in enumerate(input_str):
|
|
if char.isupper():
|
|
snake_str += "_" + char.lower()
|
|
|
|
# if char is lowercase but proceeded by a digit:
|
|
elif input_str[index - 1].isdigit() and char.islower():
|
|
snake_str += "_" + char
|
|
|
|
# if char is a digit proceeded by a letter:
|
|
elif input_str[index - 1].isalpha() and char.isnumeric():
|
|
snake_str += "_" + char.lower()
|
|
|
|
# if char is not alphanumeric:
|
|
elif not char.isalnum():
|
|
snake_str += "_"
|
|
|
|
else:
|
|
snake_str += char
|
|
|
|
# remove leading underscore
|
|
if snake_str[0] == "_":
|
|
snake_str = snake_str[1:]
|
|
|
|
return snake_str
|
|
|
|
|
|
if __name__ == "__main__":
|
|
from doctest import testmod
|
|
|
|
testmod()
|