Does importing a specific function from a module is a faster process than importing the whole module?
That is, is from module import x debugs faster than import module?
I would say there is little or no peformance difference, as importing a module for the first time will execute the entire module - all classes, variables and functions are all built, regardless of the actually symbol you need. 
The 2nd time you import the module in the same program that will be much quicker, as the module is not reloaded, and all existing definitions are used.
Debugging issues in importing modules in Python