from-root

Usage guide

Are you fed up with that annoying FileNotFoundError when your working directory turns out to be something different from what you expected? Or, maybe, you are looking for an easy and robust way of declaring paths to configs and any data files in your project? Yeah, that drives us all crazy.

The package is really tiny, there are two function:

• from_root helps with declaring absolute paths relative to your project root
• from_here comes in handy when you want to declare a path relative to the current file

They are dead simple to use.

Let's assume we have a project with the next structure:

├── .git  # OPTIONAL. See explanation below
├── .project-root  # OPTIONAL. See explanation below
├── config.json  
├── assets  
│ ├── animation.gif  
│ └── logo.png  
└── package  
    ├── __init__.py
    ├── data.csv    
    ├── script.py
    ├── FROM_HERE_DEMO.py
    └── inner_package  
      ├── FROM_ROOT_DEMO.py  
      ├── __init__.py
      └── insanely
          └── deep
              └── dir
                  └── file.txt

from_root examples:

# <PROJECT_ROOT>/package/inner_package/FROM_ROOT_DEMO.py
from from_root import from_root

CONFIG_PATH = from_root('config.json')

PACKAGE_DATA_PATH = from_root('package', 'data.csv')

# `from_root` returns pathlib.Path object
# so we can take advantage of its fantastic "/" syntax
ASSETS_DIR = from_root('assets')
ANIMATION_PATH = ASSETS_DIR / 'animation.gif'
LOGO_PATH = ASSETS_DIR / 'logo.png'

# no matter how deep it's located
FILE_TXT_PATH = from_root('package', 'inner_package', 'insanely', 'deep', 'dir', 'file.txt')

# If `mkdirs` is set to True (False by default), all *args will be treated as dir names 
# and created for you. 
# If a directory already exists, nothing happens.

import pickle

RESULTS_DIR = from_root('package', 'deep', 'results', 'dir', mkdirs=True)
results = {
    'ones': [1, 1, 1],
    'zeros': [2, 2, 2]
}
for name, data in results.items():
    path = RESULTS_DIR / f'{name}.pkl'
    # `FileNotFoundError` is not raised because `from_root` has created all non-existing directories
    with path.open('wb') as file:
        pickle.dump(data, file)

# WARNING: don't do this, you'll end up with data.json directory:
with from_root('results', 'data.json', mkdirs=True).open('w') as file:
    ...

# Do this instead:
with (from_root('results', mkdirs=True) / 'data.json').open('w') as file:
    ...

from_here examples:

# <PROJECT_ROOT>/package/FROM_HERE_DEMO.py
from from_root import from_here

# The only difference from `from_root` is that `from_here` allows you to declare relative paths
# I think the examples speak for themselves quite good. 
# Take a look at tree above and compare with `from_root` examples

CONFIG_PATH = from_here('data.csv')
FILE_TXT_PATH = from_here('inner_package', 'insanely', 'deep', 'dir', 'file.txt')

How does it work?

When from_root is called, folders in the current traceback are looked through one by one in order to find .git directory or .project-root file (might be empty; you have to create it on your own). The first one that contains at least one of them are considered as a root directory.