months to pay off credit card with tests and clean up previous

Author: Matthew Shirtliffe

password_strength_indicator/app.py

@@ -35,45 +35,9 @@ def password_validator(password):
     elif len(password) >= 8 and special_characters_regex.search(password):
         print(f'The password \'{password}\' is a very strong password')
 
-def prompt_get_strings():
-    print('Enter two strings and I\'ll tell you if they\nare anagrams: ')
-
-
-def get_first_string():
-
-    while True:
-        first_string = input('Enter the first string: ')
-        
-        if len(first_string) >=3:
-            return first_string
-        else:
-            print('A valid input is required')
-
-
-def get_second_string():
-
-    while True:
-        second_string = input('Enter the second string: ')
-        
-        if len(second_string) >=3:
-            return second_string
-        else:
-            print('A valid input is required')
-
-
-def is_anagram(first_string, second_string):
-
-    return sorted(first_string) == sorted(second_string) 
-
-
-def print_is_anagram(first_string, second_string):
-    if(is_anagram(first_string, second_string)):
-        print(f'{first_string} and {second_string} are anagrams.')
 
 if __name__ == "__main__":
 
     print_header()
-    prompt_get_strings()
-    first_string = get_first_string()
-    second_string = get_second_string()
-    print_is_anagram(first_string, second_string)
+    password = get_password()
+    password_validator(password)

pay_off_credit_card/app.py

@@ -0,0 +1,63 @@
+import math
+
+def print_header():
+    """ Print header 
+    """
+    header_text = ''
+    TEXT = f' Months to Pay Off a Credit Card \n'
+    line = '-' * len(TEXT)
+    line += '\n'
+
+    header_text += line
+    header_text += TEXT
+    header_text += line
+    print(header_text)
+
+
+def get_balance():
+
+    while True:
+        try:
+            balance = input('What is your balance? ')
+            return int(balance)
+        except ValueError:
+            print('A valid input is required')
+
+
+def get_apr():
+
+    while True:
+        try:
+            apr = input('What is the APR on the card (as a percent)? ')
+            return int(apr)
+        except ValueError:
+            print('A valid input is required')
+
+
+def get_monthly_payments():
+
+    while True:
+        try:
+            monthly_payment = input('What are the monthly payment you can make? ')
+            return int(monthly_payment)
+        except ValueError:
+            print('A valid input is required')
+
+
+def calculate_months_until_paid_off(balance, apr, monthly_payments):
+    apr = apr/100
+    apr = apr/365
+    months_until_paid_off = (-1/30) * math.log(1+(balance/monthly_payments)*(1-(1+apr)**30),10)/math.log(1+apr,10)
+    return math.ceil(months_until_paid_off)
+
+def print_months_take_to_pay(months):
+    print(f'It will take you {months} months to pay off this card')
+
+if __name__ == "__main__":
+    print_header()
+    balance = get_balance()
+    apr = get_apr()
+    monthly_payments = get_monthly_payments()
+    months_until_paid_off = calculate_months_until_paid_off(balance, apr, monthly_payments)
+    print_months_take_to_pay(months_until_paid_off)
+

pay_off_credit_card/tests/__init__.py

@@ -0,0 +1,51 @@
+from unittest import TestCase
+from unittest.mock import patch
+import app
+
+class AppTest(TestCase):
+
+    def test_print_header(self):
+        
+        expected = '----------------------------------\n Months to Pay Off a Credit Card \n----------------------------------\n'
+        with patch('builtins.print') as mocked_print:
+            app.print_header()
+            mocked_print.assert_called_with(expected)
+
+    def test_get_balance(self):
+
+        expected = 'What is your balance? '
+        with patch('builtins.input') as mocked_input:
+            with patch('builtins.print') as mocked_print:
+                mocked_input.side_effect = ('' , '5000')
+                balance = app.get_balance()
+                mocked_print.assert_called_with('A valid input is required')
+                mocked_input.assert_called_with(expected)
+                self.assertEqual(balance, 5000)
+
+    def test_get_apr(self):
+        expected = 'What is the APR on the card (as a percent)? '
+        with patch('builtins.input') as mocked_input:
+            with patch('builtins.print') as mocked_print:
+                mocked_input.side_effect = ('' , '12')
+                apr = app.get_apr()
+                mocked_print.assert_called_with('A valid input is required')
+                mocked_input.assert_called_with(expected)
+                self.assertEqual(apr, 12)
+
+    def test_get_monthly_payments(self):
+        expected = 'What are the monthly payment you can make? '
+        with patch('builtins.input') as mocked_input:
+            with patch('builtins.print') as mocked_print:
+                mocked_input.side_effect = ('' , '100')
+                monthly_payments = app.get_monthly_payments()
+                mocked_print.assert_called_with('A valid input is required')
+                mocked_input.assert_called_with(expected)
+                self.assertEqual(monthly_payments, 100)
+
+    def test_print_months_take_to_pay(self):
+        
+        months = 70
+        expected = f'It will take you {months} months to pay off this card'
+        with patch('builtins.print') as mocked_print:
+            app.print_months_take_to_pay(months)
+            mocked_print.assert_called_with(expected)

pay_off_credit_card/tests/system/__init__.py

@@ -0,0 +1,12 @@
+from unittest import TestCase
+import app
+
+class PayOffCreditCardTest(TestCase):
+    
+    def test_calculate_months_until_paid_off(self):
+        balance = 5000
+        apr = 12
+        monthly_payments = 100
+        
+        months_until_paid_off = app.calculate_months_until_paid_off(balance, apr, monthly_payments)
+        self.assertEqual(months_until_paid_off, 70)