Luhn Algorithm Completed

README.md

@@ -8,6 +8,10 @@
 <br>
 *Checking digits with a digit!*
 
+![Sample Parity](./art/parity.png)  ![Sample UPC](./art/upc.png)
+
+![Sample ISBN](./art/isbn.png) ![Sample Luhn](./art/luhn.png)
+
 ## Installation
 ```shell
 pip install checkdigit
@@ -16,8 +20,20 @@ Or download the project [here](https://github.com/harens/checkdigit/archive/mast
 ## Features
 - Add a parity digit to a string of binary
 - ISBN
-    - Validate both ISBN-10 and ISBN-13 codes
-    - Determine missing digits
-    - Calculate check digits
+    - Validates both ISBN-10 and ISBN-13 Codes
+    - Determines Missing Digits
+    - Calculates Check Digits
+- UPC
+    - Evaluates Check Digits
+    - Validates UPC Codes
+- Luhn
+    - Validates Credit Cards, IMEI Numbers, and more!
+    - Determines Check Digits
+
+
+## Tests
+The test folder can be found here [here](https://github.com/harens/checkdigit/tree/master/tests)
+
+You can run the tests by running `python tests.py`
 ## License
 This project is licensed under the [GNU General Public License v3.0](https://github.com/harens/checkdigit/blob/master/LICENSE)

checkdigit/isbn.py

@@ -36,7 +36,7 @@ def isbn13calculate(data, function_name='isbn'):
     if function_name == 'isbn':
         mod_number = 0
     else:
-        mod_number = 1
+        mod_number = 1  # Used for UPC
     total_sum = 0
     position_counter = 1  # 1 based indexing for data
     for item in data:

checkdigit/luhn.py

@@ -13,3 +13,28 @@
 # GNU General Public License for more details.
 # You should have received a copy of the GNU General Public License
 # along with checkdigit.  If not, see <http://www.gnu.org/licenses/>.
+
+
+def luhn_calculate(data):
+    position_counter = 1
+    total_sum = 0
+    for item in data[::-1]:  # Reverses String
+        item = int(item)
+        if position_counter % 2 == 1:
+            add_value = item * 2
+            if add_value > 9:
+                for number in str(add_value):  # Adds individual digits together
+                    total_sum += int(number)
+            else:
+                total_sum += add_value
+        else:
+            total_sum += item
+        position_counter += 1
+    final_result = 10 - (total_sum % 10)
+    if final_result == 10:
+        return '0'
+    return str(final_result)
+
+
+def luhn_validate(data):
+    return luhn_calculate(data[:-1]) == data[-1]

setup.py

@@ -23,7 +23,7 @@
 
 setup(
     name="checkdigit",
-    version="0.0.3",
+    version="0.0.4",
     description="Checking digits with a digit!",
     long_description=long_description,
     long_description_content_type="text/markdown",

tests/config.py

@@ -27,7 +27,9 @@ def test(function, value, function_name):
     if 'parity' in function_name:
         file_name = 'test_parity.py'
     elif 'upc' in function_name:
-        file_name = 'test_upc'
+        file_name = 'test_upc.py'
+    elif 'luhn' in function_name:
+        file_name = 'test_luhn.py'
     else:
         file_name = 'test_isbn'
     global total_tests

tests/test_luhn.py

@@ -0,0 +1,44 @@
+# /usr/bin/env python
+
+# This file is part of checkdigit.
+
+# checkdigit is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# checkdigit is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# You should have received a copy of the GNU General Public License
+# along with checkdigit.  If not, see <http://www.gnu.org/licenses/>.
+
+import sys
+import time
+from config import test
+
+sys.path.append("../")  # Go back a directory
+from checkdigit import luhn
+
+start_time = time.time()
+
+test(luhn.luhn_calculate('53251309870224'), '3', 'luhn_calculate(1)')
+test(luhn.luhn_calculate('601195843045086'), '9', 'luhn_calculate(2)')
+test(luhn.luhn_calculate('543669577125419'), '0', 'luhn_calculate(3)')
+test(luhn.luhn_calculate('436076111511668'), '6', 'luhn_calculate(4)')
+test(luhn.luhn_calculate('37266630277430'), '0', 'luhn_calculate(5)')
+test(luhn.luhn_calculate('91497796683515'), '3', 'luhn_calculate(6)')
+test(luhn.luhn_calculate('10408772972296'), '9', 'luhn_calculate(7)')
+
+test(luhn.luhn_validate('541756116585277'), True, 'luhn_validate(1)')
+test(luhn.luhn_validate('526012730485489'), True, 'luhn_validate(2)')
+test(luhn.luhn_validate('515853022176176'), True, 'luhn_validate(3)')
+test(luhn.luhn_validate('6011365035868968'), True, 'luhn_validate(4)')
+test(luhn.luhn_validate('372098369216316'), True, 'luhn_validate(5)')
+test(luhn.luhn_validate('4556098986775827'), True, 'luhn_validate(6)')
+
+finish_time = time.time()
+
+
+def luhn_time():
+    return finish_time - start_time

tests/tests.py

@@ -17,7 +17,8 @@
 
 import test_isbn
 import test_parity
-import config
 import test_upc
+import test_luhn
+import config
 
-config.final_output(test_isbn.isbn_time() + test_parity.parity_time() + test_upc.upc_time())
+config.final_output(test_isbn.isbn_time() + test_parity.parity_time() + test_upc.upc_time() + test_luhn.luhn_time())