Welcome to Stack Overflow. This is not a question about programming or about a programming-specific tool. It is therefore technically off-topic for StackOverflow. A better place to post this question would be superuser.com. With that said, it is a problem that other programmers have likely hit, so I don't personally have an issue with seeing this question here. — CryptoFool 45 secs ago

What is user, with a lower case u? You import user but there's nothing with that name in the User.py file you showed. Tangentially, your code looks irritating to experienced Python programmers. Everything is annoyingly private and there are useless getters and setters everywhere. — timgeb 56 secs ago

Hi! Welcome to Stackoverflow! Please can you give us more information about your attempts? See the guidelines of Stackoverflow to post great questions :) Take a look also to the StackOverflow tour. — gianluca aguzzi 11 secs ago

Another option is to put the implementation in separate .tcc files and include them at the end of the .hpp header file. See softwareengineering.stackexchange.com/a/375323/381883. Besides I don't think there is any other way. — Mansoor Ahmed Memon just now

Stack Overflow is not a free code translation service. We're here to build a giant FAQ with answers to questions that other programmers might have; if you try to do this yourself and run into a specific problem, a narrowly tailored question about that problem is much more likely to be well received (assuming nobody else already asked about that same issue here in the past). — Charles Duffy 53 secs ago

@tripleee I posted the solution in a comment and not in an answer and voted to close the question with the reason "about general computing hardware and software" because that is not a question being on-topic for Stack Overflow according to What types of questions should I avoid asking? and What topics can I ask about here? It is not about code written by Siddikur on which the help of other programmers is needed to get it working and it is not about a tool directly involved in programming. — Mofi 13 secs ago

@tripleee Git is a version control system. It is mainly used by programmers to manage source code as it is designed for this purpose, but I know people using Git as version control system with not a least one source code file in their branches. There is the Git documentation in multiple languages. There is explained on many pages that Git CMD uses the Windows command processor. Microsoft documented also the Windows commands. — Mofi 1 min ago

Open letter to students with homework problems and How to ask homework questions: Make a genuine attempt yourself, show your code, ask a specific question. — kaylum 29 secs ago

Welcome to the site! Please read Open letter to students with homework problems — David Makogon 38 secs ago