Should import statements always be at the top of a module?

Question

However, if the class/method/function that I am importing is only used in rare cases, surely it is more efficient to do the import when it is needed?

Isn't this:

class SomeClass(object):

    def not_often_called(self)

   from datetime import datetime

   self.datetime = datetime.now()

more efficient than this?

from datetime import datetime

class SomeClass(object):

    def not_often_called(self):

         self.datetime = datetime.now()

Answer 1

Actually, yes there are many benefits of putting import statements at the top of a module some are as follows:-

• When you put the imports at the top of the module it is fine, why because it is like a trivial cost where you only pay once and use as many times as you want.

• Another reason why we put them at the top if you won’t put them at the top and you are putting the imports within a function will cause calls to that function in a longer time.

• To make your code more efficient, you should put the import statement at the top.