Excel Library for Python 3

[buran]

there is no functions to deal with encryption

"encryption" is general term (i.e. not excel-specific) and you need to be more specific what you want to do:

• Apply some general encryption algorithm on excel file (i.e. in this case it's irrelevant that it's an excel file, it will work on any file all the same).
  
• Password protect excel file using built-in excel functionality, i.e. make the excel file password protected.
  
• Encrypt the content in some/all cell(s) in the excel file
  
• Something else (what?) ...
  

Also there are other packages to work with excel, e.g. xlwings