datafolder 0.0.4

Install and access data files (conf, json, sqlite3, ...) in an easy way.

datafolder is a small python library that makes it very easy to install the data files of your package and access them later.

If you want to install some data files (conf, sqlite, csv, …) to a place like the user’s home directory and find it difficult with setuptools then here is some help.

WARNING: this is pre-alpha software!!!

First, lets make life easier and use some ‘configuration by convention’.

I assume that (1) you have layout your project like:

MANIFEST.in
README.rst
setup.py
mypkg
    |_ __init__.py
    |_ mypkg.conf
    |_ mypkg.db
    |_ ...

And that (2) you want to put a folder, in the home directory of the user (in Windows will be in %APPDATA%), with your data files (conf, csv, …) inside. This folder will have the name of your package (preceded with a ‘.’ in UNIX systems), let us say ‘.mypkg’ and, of course, with the right permissions (it will work with sudo pip install mypkg). For virtual environements these files will be put at the root of the environement.

How to do it?

Use the following template for your setup.py (just enter at a terminal datafolder_mktpl if you already installed datafolder):

import sys
import pkg_resources
from setuptools import setup
from datafolder import Installer


# write the name of the package (in this case 'mypkg'!)
MYPKG = 'mypkg'                                             #<-- ADAPT THIS

# mypkg supports these python versions?
SUPPORT = ((2, 6), (2, 7), (3, 1), (3, 2), (3, 3), (3, 4))  #<-- ADAPT THIS

# list of data files in mypkg (just the names)
MYDATAFILES = ['mypkg.conf', 'mypkg.db']                    #<-- ADAPT THIS


# (many people get confused with the next step...)


# tell setup were these files are in your package
# (I assume that are together with the first __init__.py)
MYRESOURCES = []
for datafile in MYDAFILES:
    MYRESOURCES.append(pkg_resources.resource_filename(MYPKG, datafile))


# now, create the installer
installer = Installer(sys.argv)

# use the installer to check supported python versions
installer.support(SUPPORT)

# create the data folder and tell setup to put the data files there
DATAPATH = installer.data_path(MYPKG)
data_files = [(DATAPATH, MYRESOURCES)]

# setup can now do his thing...
setup(
    name=MYPKG,
    data_files=data_files,
    install_requires=["datafolder>=0.0.4"],                 # <-- IMPORTANT
    ...                                                     # <-- ADAPT THIS
)

# but we are NOT READY, in some cases the data files
# don't have the appropriate permissions,
# let us fix that...
installer.pos_setup(MYDATAFILES)

And that is all!

“But, I have a reverse problem, how I access these files in my code?” I heard you say.

Very easy, in your code:

from datafolder import DataFolder

data = DataFolder('mypkg')

# now you can get the full path of each data file, e.g.
conffile = data.files['mypkg.conf']

# do your thing... (read, write, ...)

For your convinience, the DataFolder class discovers the location of the data folder for you and provides attributes and methods that make it easy to handle the files presente in the data folder.

Feedback, please!