CODEWITHSUNDEEP
python
Deleted
Deleted

Reputation: 4217

Python: Custom package delivered with script and ways of importing it

I am trying to grok the way packages work in Python. My goal is to only require that Python is installed, the users should simply be able to check out the script repository and run it.

The relevant files (output of ls TestPackage.py Mypackage/):

TestPackage.py

Mypackage/:
__init__.py
SomeClass.py

Contents of TestPackage.py:

from Mypackage import SomeClass

print "Hello from TestPackage.py"

the_instance = SomeClass()

the_instance.hi()

Contents of Mypackage/_init_.py:

class InsideInitPy():
    def hi(self):
        print "Hi from InsideInitPy! (when importing package)"

InsideInitPy().hi()

Contents of Mypackage/SomeClass.py:

class SomeClass():
    def hi(self):
        print "Hi from SomeClass in the package! (using explicit call)"

When running the test script python TestPackage.py:

Hi from InsideInitPy! (when importing package)
Hello from TestPackage.py
Traceback (most recent call last):
  File "TestPackage.py", line 5, in <module>
    the_instance = SomeClass()
TypeError: 'module' object is not callable

The line producing an error is the_instance = SomeClass(). As Hi from InsideInitPy! (when importing package) is written to the console when importing it seems the package can be found.

How do I get the example working (as well as pros and cons to) using these variants of first line in TestPackage.py with:

  1. from Mypackage import SomeClass
  2. from Mypackage import *
  3. import Mypackage

Does it affect the import if the user is standing in the same directory as TestPackage.py or not?

Upvotes: 1

Views: 128

Answers (2)

Katriel
Katriel

Reputation: 123632

Don't confuse classes with modules.

You have a file SomeClass.py. Files correspond to modules. So import SomeClass gives you a module.

Inside SomeClass.py you have a class definition. That class is SomeClass.SomeClass. So you would need to write 

the_instance = SomeClass.SomeClass()

Alternatively, you could import the class SomeClass from the module MyPackage.SomeClass:

from MyPackage.Someclass import SomeClass

Upvotes: 3

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798566

Python is not Java.

from Mypackage.SomeClass import SomeClass

Upvotes: 3

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