python 3.x - __file__ does not exist in Jupyter Notebook

Question

I'm on a Jupyter Notebook server (v4.2.2) with Python 3.4.2 and I want to use the global name __file__, because the notebook will be cloned from other users and in one section I have to run:

def __init__(self, trainingSamplesFolder='samples', maskFolder='masks'):
    self.trainingSamplesFolder = self.__getAbsPath(trainingSamplesFolder)
    self.maskFolder = self.__getAbsPath(maskFolder)

def __getAbsPath(self, path):
    if os.path.isabs(path):
        return path
    else:
        return os.path.join(os.path.dirname(__file__), path)

The __getAbsPath(self, path) checks if a path param is a relative or absolute path and returns the absolute version of path. So I can use the returned path safely later.

But I get the error

NameError: name '__file__' is not defined

I searched for this error online and found the "solution" that I should better use sys.argv[0], but print(sys.argv[0]) returns

/usr/local/lib/python3.4/dist-packages/ipykernel/__main__.py

But the correct notebook location should be /home/ubuntu/notebooks/.

Thanks for the reference How do I get the current IPython Notebook name from Martijn Pieters (comments) the last answer (not accepted) fits perfect for my needs:

print(os.getcwd())

/home/ubuntu/notebooks

Answer 1

If you want to get path of the directory in which your script is running, I would highly recommend using,

os.path.abspath('')

Advantages

• It works from Jupyter Notebook
• It work from REPL
• It doesn't require Python 3.4's pathlib

Please note that one scenario where __file__ has advantage is when you are invoking python from directory A but running script in directory B. In that case above as well as most other methods will return A, not B. However for Jupyter notbook, you always get folder for .ipyn file instead of the directory from where you launched jupyter notebook.