diff --git a/banking_app/login.py b/banking_app/login.py
index 2bbab36..9d0ce1f 100644
--- a/banking_app/login.py
+++ b/banking_app/login.py
@@ -1,5 +1,5 @@
 # login.py - Placeholder for login functionality
-
+import csv
 def login(username, password):
     """
     Handles the user login process by verifying the provided username and password.
@@ -33,3 +33,24 @@ def login(username, password):
     - bool: `True` if login is successful, `False` if login fails, or raises a `ValueError` for invalid input.
 
     """
+
+    if not username or not password:
+        raise ValueError
+    
+    for char in username:
+        if not char.isalnum():
+            raise ValueError()
+        
+
+    path = r"C:\Users\User\Byte-me-python\database.csv" 
+    with open(path, mode='r', newline='', encoding='utf-8') as file:
+        reader = csv.reader(file)
+        for row in reader:
+
+            if username in row and row[username] == password:
+                return True
+            else:
+                return False
+
+    return True
+
diff --git a/banking_app/signup.py b/banking_app/signup.py
index a920e5b..acf73e4 100644
--- a/banking_app/signup.py
+++ b/banking_app/signup.py
@@ -1,5 +1,5 @@
 # signup.py - Placeholder for signup functionality
-
+import re
 def signup(username, password, email):
     """
     Handles the user signup process by validating the provided username, password, and email.
@@ -35,3 +35,19 @@ def signup(username, password, email):
     Returns:
     - bool: `True` if the signup is successful, otherwise raises a `ValueError` for invalid input.
     """
+
+    if not username or not password or not email:
+        raise ValueError() 
+    
+    email_regex = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
+    if not re.match(email_regex, email):
+        raise ValueError()
+    
+ 
+    if len(password) < 8 or not any(c.isupper() for c in password) or not any(c.islower() for c in password) or not any(c.isdigit() for c in password):
+        raise ValueError()
+
+    if password.isdigit() or password.lower() in ["password", "123456", "qwerty"]:
+        raise ValueError()
+
+    return True
\ No newline at end of file
diff --git a/functions_to_test.py b/functions_to_test.py
index 330fa02..0096c74 100644
--- a/functions_to_test.py
+++ b/functions_to_test.py
@@ -1,34 +1,97 @@
 # Placeholder functions for Python basics, to be implemented later
 
 def add_numbers(a, b):
-    pass
+    if not isinstance(a, (int,float)) or not isinstance(b, (int,float)):
+        raise TypeError
+    
+    return a + b
+
 
 def find_maximum(a, b, c):
-    pass
+    return max(a,b,c)
 
 def is_palindrome(string):
-    pass
+    if not type(string) == str:
+        raise TypeError
+    
+    return string == string[::-1]
 
 def count_word_occurrences(text, word):
-    pass
+    if type(text) == int:
+        raise TypeError
+    return text.lower().count(word)
 
 def read_file_lines(filepath):
-    pass
+    with open(filepath, 'r', errors="ignore") as file:
+        return file.readlines()
 
 def factorial(n):
-    pass
+    if not isinstance(n, int):
+        raise TypeError()
+    
+    if n < 0:
+        raise ValueError()
+    
+    if n == 0 or n == 1:  
+        return 1
+    
+    return n * factorial(n - 1)
+
 
 def is_prime(n):
-    pass
+    if not isinstance(n, int):
+        raise TypeError()
+    
+    if n < 0:
+        raise ValueError()
+    
+    if n < 2:
+        return False  
+    
+    for i in range(2, int(n**0.5) + 1):
+        if n % i == 0:
+            return False
+    
+    return True
 
 def sort_numbers(numbers):
-    pass
+    for i in numbers:
+        if not isinstance(i, int):
+            raise TypeError()
+        
+    return sorted(numbers)
 
 def factorial(n):
-    pass
+    if not isinstance(n, int):
+        raise TypeError()
+    
+    if n < 0:
+        raise ValueError()
+    
+    if n == 0 or n == 1:  
+        return 1
+    
+    return n * factorial(n - 1)
+
 
 def fibonacci(n):
-    pass
+    if not isinstance(n, int):
+        raise TypeError()
+    
+    if n < 0:
+        raise ValueError()
+    
+    if n == 0:
+        return 0
+    if n == 1:
+        return 1
+
+    a, b = 0, 1
+    for _ in range(2, n + 1):
+        a, b = b, a + b
+    
+    return b
+    
 
 def tower_of_hanoi(n, source, auxiliary, target):
     
@@ -52,7 +115,13 @@ def tower_of_hanoi(n, source, auxiliary, target):
 
 class Person:
     def __init__(self, name, age):
-        pass
+        if not isinstance(name, str):
+            raise TypeError("Name must be a string.")
+        if not isinstance(age, int):
+            raise TypeError("Age must be an integer.")
+        
+        self.name = name
+        self.age = age
 
 
 if __name__ == "__main__":
diff --git a/tests/test_functions.py b/tests/test_functions.py
index ae682d2..cfa9a0e 100644
--- a/tests/test_functions.py
+++ b/tests/test_functions.py
@@ -43,10 +43,9 @@ def test_factorial_0_and_1(self):
         1)
 
 
-    def test_factorial_negative(self):
-        self.assertEqual(factorial(-1),
-        "")
-
+def test_factorial_negative(self):
+    with self.assertRaises(ValueError):
+        factorial(-1) 
     
     def test_factorial_5(self):
         self.assertEqual(factorial(5),