[Tutor] import statements in functions?

[Marcus Goldfish]

Is there a convention to be considered for deciding if import
statements should be included in a function body?  For example, which
of these two module layouts would be preferable:

     # --- MyModule1.py -----
     import foo1, foo2, foo3
     import foo_special
    
     # several coherent functions here

     def specialFunction():
          doSomethingSpecial()

or the "embedded import" version:

     # --- MyModule2.py -----
     import foo1, foo2, foo3
     import foo_rare
    
     # several coherent functions here

     def specialFunction():
          import foo_special
          doSomethingSpecial()

Also, does the choice have any impact on performance/space/etc.?  And
will the import function get called each time (and possibly ignored)
in the second version?

The reason I consider the second form is that the module foo_special
is only used by the code in specialFunction(), and detracts (IMHO)
from understanding the rest of the code in the module.

Thanks,
Marcus