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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:
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"""
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Transforms a camelCase (or PascalCase) string to snake_case
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>>> camel_to_snake_case("someRandomString")
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'some_random_string'
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>>> camel_to_snake_case("SomeRandomStr#ng")
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'some_random_str_ng'
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>>> camel_to_snake_case("123someRandom123String123")
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'123_some_random_123_string_123'
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>>> camel_to_snake_case("123SomeRandom123String123")
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'123_some_random_123_string_123'
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>>> camel_to_snake_case(123)
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Traceback (most recent call last):
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...
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ValueError: Expected string as input, found <class 'int'>
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"""
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# check for invalid input type
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if not isinstance(input_str, str):
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msg = f"Expected string as input, found {type(input_str)}"
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raise ValueError(msg)
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snake_str = ""
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for index, char in enumerate(input_str):
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if char.isupper():
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snake_str += "_" + char.lower()
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# if char is lowercase but proceeded by a digit:
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elif input_str[index - 1].isdigit() and char.islower():
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snake_str += "_" + char
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# if char is a digit proceeded by a letter:
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elif input_str[index - 1].isalpha() and char.isnumeric():
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snake_str += "_" + char.lower()
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# if char is not alphanumeric:
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elif not char.isalnum():
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snake_str += "_"
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else:
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snake_str += char
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# remove leading underscore
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if snake_str[0] == "_":
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snake_str = snake_str[1:]
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return snake_str
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if __name__ == "__main__":
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from doctest import testmod
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testmod()
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