"""Configuration options for datasets


Especially, the locations of data files.
"""

import os, sys, logging
def _logger():  return logging.getLogger('pylearn.datasets.config')
def debug(*msg): _logger().debug(' '.join(str(m) for m in msg))
def info(*msg): _logger().info(' '.join(str(m) for m in msg))
def warn(*msg): _logger().warn(' '.join(str(m) for m in msg))
def warning(*msg): _logger().warning(' '.join(str(m) for m in msg))
def error(*msg): _logger().error(' '.join(str(m) for m in msg))


def env_get(key, default, key2 = None):
    if key2 and os.getenv(key) is None:
        key=key2
    if os.getenv(key) is None:
        if env_get.first_warning:
            warning("Environment variable", key, 'is not set. Using default of', default)
            env_get.first_warning = False
        return default
    else:
        return os.getenv(key)
env_get.first_warning = True

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