Added to maths and strings (#1642)

* Added to maths and strings

* added changes suggest by cclauss

strings/lower.py

@@ -0,0 +1,29 @@
+def lower(word: str) -> str:
+
+    """ 
+    Will convert the entire string to lowecase letters 
+    
+    >>> lower("wow")
+    'wow'
+    >>> lower("HellZo")
+    'hellzo'
+    >>> lower("WHAT")
+    'what'
+    
+    >>> lower("wh[]32")
+    'wh[]32'
+    >>> lower("whAT")
+    'what'
+    """
+
+    # converting to ascii value int value and checking to see if char is a capital letter
+    # if it is a capital letter it is getting shift by 32 which makes it a lower case letter
+    return "".join(
+        chr(ord(char) + 32) if 65 <= ord(char) <= 90 else char for char in word
+    )
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()

strings/split.py

@@ -0,0 +1,33 @@
+def split(string: str, seperator: str = " ") -> list:
+    """
+    Will split the string up into all the values seperated by the seperator (defaults to spaces)
+    
+    >>> split("apple#banana#cherry#orange",seperator='#')
+    ['apple', 'banana', 'cherry', 'orange']
+    
+    >>> split("Hello there")
+    ['Hello', 'there']
+    
+    >>> split("11/22/63",seperator = '/')
+    ['11', '22', '63']
+    
+    >>> split("12:43:39",seperator = ":")
+    ['12', '43', '39']
+    """
+
+    split_words = []
+
+    last_index = 0
+    for index, char in enumerate(string):
+        if char == seperator:
+            split_words.append(string[last_index:index])
+            last_index = index + 1
+        elif index + 1 == len(string):
+            split_words.append(string[last_index : index + 1])
+    return split_words
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()

strings/upper.py

@@ -0,0 +1,26 @@
+def upper(word: str) -> str:
+    """ 
+    Will convert the entire string to uppercase letters 
+    
+    >>> upper("wow")
+    'WOW'
+    >>> upper("Hello")
+    'HELLO'
+    >>> upper("WHAT")
+    'WHAT'
+    
+    >>> upper("wh[]32")
+    'WH[]32'
+    """
+
+    # converting to ascii value int value and checking to see if char is a lower letter
+    # if it is a capital letter it is getting shift by 32 which makes it a capital case letter
+    return "".join(
+        chr(ord(char) - 32) if 97 <= ord(char) <= 122 else char for char in word
+    )
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()