diff --git a/strings/stringfunctions.py b/strings/stringfunctions.py
index e256e5ccf..dc9e1be46 100644
--- a/strings/stringfunctions.py
+++ b/strings/stringfunctions.py
@@ -1,13 +1,13 @@
 def is_upper(string: str) -> bool:
     """
     Check if all characters in the string are uppercase letters.
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are uppercase letters, False otherwise.
-    
+
     Examples:
     >>> is_upper("HELLO")
     True
@@ -16,16 +16,17 @@ def is_upper(string: str) -> bool:
     """
     return all(ord(char) >= 65 and ord(char) <= 90 for char in string)
 
+
 def is_lower(string: str) -> bool:
     """
     Check if all characters in the string are lowercase letters.
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are lowercase letters, False otherwise.
-    
+
     Examples:
     >>> is_lower("hello")
     True
@@ -34,16 +35,17 @@ def is_lower(string: str) -> bool:
     """
     return all(ord(char) >= 97 and ord(char) <= 122 for char in string)
 
+
 def is_alpha(string: str) -> bool:
     """
     Check if all characters in the string are alphabetical (letters).
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are letters, False otherwise.
-    
+
     Examples:
     >>> is_alpha("Hello")
     True
@@ -52,16 +54,17 @@ def is_alpha(string: str) -> bool:
     """
     return all(char.isalpha() for char in string)
 
+
 def is_alnum(string: str) -> bool:
     """
     Check if all characters in the string are alphanumeric (letters or digits).
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are letters or digits, False otherwise.
-    
+
     Examples:
     >>> is_alnum("Hello123")
     True
@@ -70,16 +73,17 @@ def is_alnum(string: str) -> bool:
     """
     return all(char.isalnum() for char in string)
 
+
 def is_decimal(string: str) -> bool:
     """
     Check if all characters in the string are decimal digits.
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are decimal digits, False otherwise.
-    
+
     Examples:
     >>> is_decimal("12345")
     True
@@ -88,16 +92,17 @@ def is_decimal(string: str) -> bool:
     """
     return all(char.isdigit() for char in string)
 
+
 def is_space(string: str) -> bool:
     """
     Check if all characters in the string are whitespace characters.
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if all characters in the string are whitespace characters, False otherwise.
-    
+
     Examples:
     >>> is_space("    \\t\\n")
     True
@@ -106,16 +111,17 @@ def is_space(string: str) -> bool:
     """
     return all(char.isspace() for char in string)
 
+
 def is_title(string: str) -> bool:
     """
     Check if the string is in title case (first letter of each word is capital).
-    
+
     Args:
         string (str): The input string.
-        
+
     Returns:
         bool: True if the string is in title case, False otherwise.
-    
+
     Examples:
     >>> is_title("This Is A Title Case String")
     True
@@ -124,6 +130,8 @@ def is_title(string: str) -> bool:
     """
     return string.istitle()
 
+
 if __name__ == "__main__":
     import doctest
-    doctest.testmod()
\ No newline at end of file
+
+    doctest.testmod()