What Is The Concept Of Namespace When Importing A Function From Another Module?

main.py: from module1 import some_function x=10 some_function() module1.py: def some_function(): print str(x) When I execute the main.py, it gives an error in the moduel1.py

Solution 1:

Each module has its own global name space.

from module1 import some_function
x=10some_function()

some_function uses module1.x in its definition, but you are setting x in the current module. This would work:

from module1 import some_function
import module1

module1.x = 10some_function()

Note that you can't use from module1 import x, then set x = 10, because that import simply initializes a new name x to have the same initial value as module1.x; x = 10 then gives a new value to the new variable.

Solution 2:

At the risk of sounding flippant, the rule is pretty simple: if the name hasn't been defined within the module, it simply doesn't exist.

Look at this module:

defsome_function():
    printstr(x)

It doesn't define x, so that name doesn't exist within this module. If you define x in another module, it still won't exist within this module. Even if you import this module into the other module that defines x, x still won't exist within this module.

There's no "global global" namespace. Each module has its own global namespace. Names are never implicitly shared between modules, they must always be explicitly imported.

_{The only exception to this are the builtins, which—for convenience—don't need to be explicitly imported.}