Importing

Python3

2 package types

• Regular package/folder with __init__.py

  • Can contain init instruction

• Namespace package without one, for high level packages that share name with other packages i.e

  • google/cloud/storage

  • google/cloud/pubsub

  • google and cloud should be namespace because they are shared by multiple things

# Same directory
from .config import config
from .routes import user as user_blueprint


# Sub directory
from sound.effects import echo

Alternatives

import sound.effects.echo
sound.effects.echo.echofilter(input, output, delay=0.7, atten=4)

from sound.effects import * #bad practice

Python2

Importing from Same Dir

Make an empty file called init.py in the same directory as the files. That will signify to Python that it's "ok to import from this directory". Then just:

from .user import User
from .dir import Dir

Importing from Subdirectory

The same holds true if the files are in a subdirectory - put an init.py in the subdirectory as well.

bin/
    main.py
    classes/
        user.py
        dir.py

main.py

from classes.user import User
from classes.dir import Dir

Importing from Sister Directory

bin/
    mary/
        walk.py
	kate/
		run.py

Yea.., you need to add the root directory to PYTHON_PATH

could also pip install -e

File IO In Imported Files

Are you trying to open a file in a package that you then import? Well that means you are getting an error because the path will be different if you run the script and import the script

__location__ = os.path.realpath(
    os.path.join(os.getcwd(), os.path.dirname(__file__)))

• join() prepends current working directory, but the documentation says that if some path is absolute, all other paths left of it are dropped. Therefore, getcwd() is dropped when dirname(file) returns an absolute path. Also, the realpath call resolves symbolic links if any are found

Then

f = open(os.path.join(__location__, 'bundled-resource.jpg'))