Source code for core.paths

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""Path management."""

import os

from . import log

__paths = {}


def _identify_folder_name(base, name):
    """
    Allows folder names to be lowercase on case-sensitive systems.
    Returns "base/name" where name is lowercase if the lower case version
    exists and the standard case version does not.

    Args:
        base: the path containing the desired folder.
        name: the standard case name of the desired folder.
    """
    normal = os.path.join(base, name)
    lower = os.path.join(base, name.lower())
    if os.path.isdir(lower) and not os.path.isdir(normal):
        return lower
    return normal


def register(name, *path_elms, **kwargs):
    """Registers a path constructed by <path_elms> under <name>.
    If multiple path elements are given, the last
    element will undergo case correction (see _identify_folder_name).

    Args:
        name: a registered name corresponding to some path segment
        path_elems: path elements, which will be joined to the root path
        allow_create:  If True, the registered path will be created if it
            does not already exist. Defaults to True.
    """
    if len(path_elms) > 1:
        __paths[name] = _identify_folder_name(os.path.join(
            *path_elms[:-1]), path_elms[-1])
    else:
        __paths[name] = path_elms[0]
    log.i('Registering path %s as %s', name, __paths[name])
    if kwargs.get('allow_create', True) and not os.path.exists(__paths[name]):
        os.makedirs(__paths[name])


def get(name, *paths):
    """Returns the path registered under <name>, or an empty string if <name>
    is not known."""
    try:
        base = __paths[name]
    except KeyError:
        base = ''
    return os.path.join(base, *paths)


def clear():
    """Clears the path cache."""
    __paths.clear()