Merge pull request #98 from PdxCodeGuild/jonpan-lab07-card-validation

jonpan submitting lab07

Author: nathanBonilla

code/jonpan/lab07.py

@@ -0,0 +1,70 @@
+#Lab07 Credit Card Validator
+
+def credit_card_validator(credit_card_number):
+    
+    #Convert the input string into a list of ints
+
+    cc_to_list = list(credit_card_number)
+
+    for i in range(len(cc_to_list)):
+        cc_to_list[i] = int(cc_to_list[i])
+
+    print(cc_to_list)
+
+    # Slice off the last digit. That is the check digit.
+
+    check_digit = cc_to_list.pop(-1)
+    # print(check_digit)
+
+    # Reverse the digits.
+
+    reversed_list = cc_to_list[::-1]
+    print(reversed_list)
+
+    # Double every other element in the reversed list (starting with the first number in the list).
+
+    # for i in range(0, len(reversed_list), 2):
+    #     reversed_list[i] = int(reversed_list[i]) * 2
+    #     print(reversed_list[i])
+
+    double_list = []
+
+    for i in range(len(reversed_list)):
+        if i % 2 == 0:
+            double_list.append(reversed_list[i] * 2)
+        else:
+            double_list.append(reversed_list[i])
+
+    print(double_list)
+
+    # Subtract nine from numbers over nine.
+
+    subtract_list = []
+
+    for i in range(len(double_list)):
+
+        if (double_list[i]) > 9:
+            subtract_list.append(double_list[i] - 9)
+        else:
+            subtract_list.append(double_list[i])
+
+    print(subtract_list)
+
+    # Sum all values.
+
+    sumall = str(sum(subtract_list))
+
+    print(sumall)
+    
+    # Take the second digit of that sum.
+
+    second_digit = sumall[1]
+
+    print(second_digit)
+
+    # If that matches the check digit, the whole card number is valid.
+
+    if second_digit == str(check_digit):
+        print("Valid!")
+
+print(credit_card_validator("4556737586899855"))