Class is not defined despite being imported

Question

I seem to have run into a really confusing error. Despite importing the .py file containing my class, Python is insistent that the class doesn't actually exist.

Class definition in testmodule.py:

class Greeter:
    def __init__(self, arg1=None):
        self.text = arg1

    def say_hi(self):
        return self.text

main.py:

#!/usr/bin/python
import testmodule

sayinghi = Greeter("hello world!")
print(sayinghi.say_hi())

I have a theory that the import is not working as it should. How do I do this correctly?

Solution 1

Use the fully-qualified name:

sayinghi = testmodule.Greeter("hello world!")

There is an alternative form of import that would bring Greeter into your namespace:

from testmodule import Greeter

Solution 2

import testmodule
# change to
from testmodule import Greeter

or

import testmodule
sayinghi = Greeter("hello world!")
# change to
import testmodule
sayinghi = testmodule.Greeter("hello world!")

You imported the module/package, but you need to reference the class inside it.

You could also do this instead

from testmodule import *

but then beware of namespace pollution