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Convert snake_case to camelCase or PascalCase (#7028) #7034

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Merged
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Oct 13, 2022
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Convert snake_case to camelCase or PascalCase (#7028) #7034

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Added snake_case to Camel or Pascal case Fixes: #7028
carlos3dx Oct 12, 2022
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carlos3dx Oct 12, 2022
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carlos3dx Oct 12, 2022
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pre-commit-ci[bot] Oct 12, 2022
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Update strings/snake_case_to_camel_pascal_case.py
carlos3dx Oct 12, 2022
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52 changes: 52 additions & 0 deletions strings/snake_case_to_camel_pascal_case.py
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def snake_to_camel_case(input: str, use_pascal: bool = False) -> str:
"""
Transforms a snake_case given string to camelCase (or PascalCase if indicated)
(defaults to not use Pascal)

>>> snake_to_camel_case("some_random_string")
'someRandomString'

>>> snake_to_camel_case("some_random_string", use_pascal=True)
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Please add a few more tests...

Suggested change
>>> snake_to_camel_case("some_random_string", use_pascal=True)
>>> snake_to_camel_case("SOME___RaNdOm_32_string", use_pascal=True)
>>> snake_to_camel_case("_some_random_string_", use_pascal=True)
>>> s = "some_random_string"
>>> snake_to_camel_case(snake_to_camel_case(s, use_pascal=True), use_pascal=False) == s
True

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Sorry, I don't get the last test, it is to convert from snake to camel/pascal, that test is converting the snake to pascal and later try to convert from pascal to camel and compare to the original snake one.

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@cclauss cclauss Oct 12, 2022 •
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Yes. We want to make sure that decode(encode(s)) == s proves that we can "roundtrip" if we have good input.

Like:
% python3

>>> "Lüsai".encode()  # Convert a str into bytes
b'L\xc3\xbcsai'
>>> "Lüsai".encode().decode() == "Lüsai"  # Roundtrip: str --> bytes --> str
True

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But the function is not to encode/decode, is to transform from snake to other.

Your given example would be more like

>>> "Lüsai".encode()  # Convert a str into bytes
b'L\xc3\xbcsai'
>>> "Lüsai".encode().encode() == "Lüsai"  # str --> bytes --> bytes
True

I think the issue is the parameter use_pascal, which signals to instead of converting snake to camel, converts it to pascal instead, thought that could make it more useful and show an example of the equivalent to other languages ternary operator. I could remove it or create snake_to_camel_case(input) and snake_to_pascal_case(input).

If you consider it necessary I can add Camel/Pascal to snake

'SomeRandomString'

>>> snake_to_camel_case("some_random_string_with_numbers_123")
'someRandomStringWithNumbers123'

>>> snake_to_camel_case("some_random_string_with_numbers_123", use_pascal=True)
'SomeRandomStringWithNumbers123'

>>> snake_to_camel_case(123)
Traceback (most recent call last):
...
ValueError: Expected string as input, found <class 'int'>

>>> snake_to_camel_case("some_string", use_pascal="True")
Traceback (most recent call last):
...
ValueError: Expected boolean as use_pascal parameter, found <class 'str'>
"""

if not isinstance(input, str):
raise ValueError(f"Expected string as input, found {type(input)}")
if not isinstance(use_pascal, bool):
raise ValueError(
f"Expected boolean as use_pascal parameter, found {type(use_pascal)}"
)

words = input.split("_")

start_index = 0 if use_pascal else 1

words_to_capitalize = words[start_index:]

capitalized_words = [word[0].upper() + word[1:] for word in words_to_capitalize]

initial_word = "" if use_pascal else words[0]

return "".join([initial_word] + capitalized_words)


if __name__ == "__main__":
from doctest import testmod

testmod()