License Key Formatter Algorithm

Author: Yenfry Herrera

LicenseKeyFormatter.py

@@ -0,0 +1,59 @@
+class LicenseKeyFormatter:
+    def __init__(self, licenseKey):
+        self.licenseKey = licenseKey.upper()
+        
+    
+    def reformatLicenseKey(self, k):
+        #first we count all the chars excluding dashes
+        newLicenseKey = []
+        
+        chars_count = 0
+        for c in self.licenseKey:
+            if c != '-':
+                chars_count += 1
+
+        #then lets define how many chars will be in our first group
+        items_by_group = chars_count % k
+        item_count = 0
+        
+        for char_idx in range(len(self.licenseKey)):
+
+            #Skip the dash char
+            if self.licenseKey[char_idx] == '-':
+                continue
+            
+            #condition to add a dash every items_by_group chars.
+            #With this condition we prevent from adding a dash at the end of the new key.
+            if item_count == items_by_group:
+
+                #we this we prevent from adding a dash at the beginning of the new key
+                if items_by_group != 0 and item_count != 0:
+                    newLicenseKey.append('-')
+
+                items_by_group = k    
+                item_count = 0
+
+            #add the current char to our new licenseKey
+            elm = self.licenseKey[char_idx]
+            newLicenseKey.append(elm)
+
+            item_count += 1
+            
+        return ''.join(c for c in newLicenseKey)
+
+    
+
+if __name__ == '__main__':
+
+    tests = [
+        {'input': {'licenseKey': '5F3Z-2e-9-w', 'k': 4}, 'expected': '5F3Z-2E9W'},
+        {'input': {'licenseKey': '2-5g-3-J', 'k': 2}, 'expected': '2-5G-3J'},
+    ]
+
+    for test in tests:
+        licenseKey = test['input']['licenseKey']
+        k = test['input']['k']
+        formatter = LicenseKeyFormatter(licenseKey)
+        formattedLicenseKey = formatter.reformatLicenseKey(k)
+
+        print('Input: (licenseKey=', licenseKey, ', k=', k, ')', ', Output: ', formattedLicenseKey, ', Expected: ', test['expected'], ', Test passed: ', ('True' if test['expected'] == formattedLicenseKey else 'False'))