Change password function

My script completes the below tasks.

Requirements

ChangePassword(oldPassword: String, newPassword: String)

Tasks

1. Code for change password function
2. Implement automate test for the created function, test cases with test data provide in each case
3. The verify password with system and similar check function should be a mock which return True/False

Password requirement

1. At least 18 alphanumeric characters and list of special chars !@#$&*
2. At least 1 Upper case, 1 lower case ,least 1 numeric, 1 special character
3. No duplicate repeat characters more than 4
4. No more than 4 special characters
5. 50 % of password should not be a number

Change password requirement

1. Old password should match with system
2. New password should be a valid password
3. password is not similar to old password < 80% match. ==================================================

Script changepasswordtask.py has all the functions for verifying old password with system, validating new password with above defined password requirement and checking similarity between old and new passwords.

1. For verifying old password with system, making use of list of password strings stored in class variable and comparing against old password passed through testcase.
2. For validating new password, passing the new password and validating against the requirements.
3. For similarity check, passing old and new passwords and comparing them.

Requirements:-
Machine with python 3 installed
If logging module is not installed, run following command

pip install -r requirements.txt

Lets run the testcase script

python testPasswordChangeTask.py

Running the Test Case script testPasswordChangeTask.py will verify if the old password matches the mock system passwords and new password matches the strong password criteria, also a similarity check for old and new passwords and outputs the logs to example.log. I have attached a sample log file.

Following cases are covered in test script :-

Case1: Valid Password  
Case2a: Single Uppercase character and single special character  
Case2b: Single Lowercase character and single digit  
Case2c: Exact 18 length character and 50% numbers  
Case2d: Exact 4 duplicated repeated character in password  
Case2e: Exact 4 special characters in password  
Case3: Password length is less then 18  
Case4: No lowercase character in password  
Case5: No uppercase character in password  
Case6: No digit in password  
Case7: No special characters in password  
Case8: No whitespace characters in password  
Case9: Duplicate repeat characters more than 4 times in password  
Case10: Special Characters more than 4 times in password  
Case11: Numbers more than 50% of the length of password  
Case12: Old password doesn't match the system  
Case13: Old password is empty  
Case14: New password not similar to old password or greater then 80% similar