Python Snake Case Conversion

Introduction

In Python, snake case is a naming convention where words are separated by underscores. This is commonly used for naming variables, functions, and other identifiers. However, sometimes we may have strings that are not in snake case and we need to convert them. In this challenge, you will be tasked with writing a Python function that converts a string to snake case.

Skills Graph

Snakecase String

Write a Python function called snake that takes a string as its argument and returns the string in snake case. The function should perform the following steps:

1. Use re.sub() to match all words in the string, str.lower() to lowercase them.
2. Use re.sub() to replace any - characters with spaces.
3. Finally, use str.join() to combine all words using _ as the separator.

Your function should be able to handle strings with a mix of uppercase and lowercase letters, spaces, hyphens, and underscores.

from re import sub

def snake(s):
  return '_'.join(
    sub('([A-Z][a-z]+)', r' \1',
    sub('([A-Z]+)', r' \1',
    s.replace('-', ' '))).split()).lower()

snake('camelCase') ## 'camel_case'
snake('some text') ## 'some_text'
snake('some-mixed_string With spaces_underscores-and-hyphens')
## 'some_mixed_string_with_spaces_underscores_and_hyphens'
snake('AllThe-small Things') ## 'all_the_small_things'

Summary

In this challenge, you learned how to write a Python function that converts a string to snake case. You used re.sub() to match and replace words in the string, str.lower() to lowercase them, and str.join() to combine them using underscores as the separator. With this knowledge, you can now easily convert strings to snake case in your Python programs.