"""Configuration options for datasets


Especially, the locations of data files.
"""

import os, sys
def env_get(key, default, key2 = None):
    if key2 and os.getenv(key) is None:
        key=key2
    if os.getenv(key) is None:
        print >> sys.stderr, "WARNING: Environment variable", key,
        print >> sys.stderr, "is not set. Using default of", default
    return default if os.getenv(key) is None else os.getenv(key)

def data_root():
    return env_get('PYLEARN_DATA_ROOT', os.getenv('HOME')+'/data', 'DBPATH')