I went to install a stock module in  my system but every time it gives me error like

yaml.constructor.ConstructorError: could not determine a constructor for the tag '!python'
  in "<byte string>", line 2, column 3:
      !python {model: ir.model.data, i ...
 
      ^

I check the code of the yml file it is same as the in odoo github file I was nothing to change in code.
I not understand way it is gives error.