Question

Which of the following cannot be pickled?

(a) Functions which are defined at the top level of a module with lambda

(b) Functions which are defined at the top level of a module with def

(c) Built-in functions which are defined at the top level of a module

(d) Classes which are defined at the top level of a module

The question was asked in an online interview.

I'm obligated to ask this question of Pickle Module in division Mapping Functions and Modules of Python

Answer 1

The correct option is (a) Functions which are defined at the top level of a module with lambda

To explain: Functions which are defined at the top level of a module with lambda cannot be pickled.