feat(day 114): add camelCase to snake_case converter with regex option

Author: JohnSunny21

FreeCodeCamp/CodingQ/CamelToSnake.py

@@ -0,0 +1,53 @@
+"""
+
+Camel to Snake
+Given a string in camel case, return the snake case version of the string using the following rules:
+
+The input string will contain only letters (A-Z and a-z) and will always start with a lowercase letter.
+Every uppercase letter in the camel case string starts a new word.
+Convert all letters to lowercase.
+Separate words with an underscore (_).
+"""
+
+import unittest
+
+class CamelToSnakeTest(unittest.TestCase):
+
+    def test1(self):
+        self.assertEqual(to_snake("helloWorld"),"hello_world")
+
+    def test2(self):
+        self.assertEqual(to_snake("myVariableName"),"my_variable_name")
+    
+    def test3(self):
+        self.assertEqual(to_snake("freecodecampDailyChallenges"),"freecodecamp_daily_challenges")
+
+
+def to_snake(camel):
+
+    snake = ''
+
+    for char in camel:
+        if char.isupper():
+            snake += '_'+char.lower()
+        else:
+            snake += char
+
+    return snake
+
+import re
+def to_snake_optimized(camel):
+    # Insert underscore before each uppercase letter
+
+    snake = re.sub(r'([A-Z])', r'_\1', s)
+    """
+    r'([A-Z])' -> raw string regex, matches uppercase letters.
+    r'_\' -> replacement string
+    => \1 means "the text matched by the first capture group".(i think there in caes of multiple capture groups like () () () when use 1 the first capture group is insert remember this just only for my sake.
+    => So it inserts _ before the uppercase letter.
+    """
+    return snake.lower()
+
+if __name__ == "__main__":
+    print(to_snake("myGuinnessRecord"))
+    unittest.main()