Source code for dateutil.zoneinfo

# -*- coding: utf-8 -*-
import logging
import os
import warnings
import tempfile
import shutil
import json

from tarfile import TarFile
from pkgutil import get_data
from io import BytesIO
from contextlib import closing

from import tzfile

__all__ = ["gettz", "gettz_db_metadata", "rebuild"]

ZONEFILENAME = "dateutil-zoneinfo.tar.gz"

# python2.6 compatability. Note that TarFile.__exit__ != TarFile.close, but
# it's close enough for python2.6
tar_open =
if not hasattr(TarFile, '__exit__'):
    def tar_open(*args, **kwargs):
        return closing(*args, **kwargs))

class tzfile(tzfile):
    def __reduce__(self):
        return (gettz, (self._filename,))

def getzoneinfofile_stream():
        return BytesIO(get_data(__name__, ZONEFILENAME))
    except IOError as e:  # TODO  switch to FileNotFoundError?
        warnings.warn("I/O error({0}): {1}".format(e.errno, e.strerror))
        return None

class ZoneInfoFile(object):
    def __init__(self, zonefile_stream=None):
        if zonefile_stream is not None:
            with tar_open(fileobj=zonefile_stream, mode='r') as tf:
                # dict comprehension does not work on python2.6
                # TODO: get back to the nicer syntax when we ditch python2.6
                # self.zones = { tzfile(tf.extractfile(zf),
                #               filename =
                #              for zf in tf.getmembers() if zf.isfile()}
                self.zones = dict((, tzfile(tf.extractfile(zf),
                                  for zf in tf.getmembers()
                                  if zf.isfile() and != METADATA_FN)
                # deal with links: They'll point to their parent object. Less
                # waste of memory
                # links = { self.zones[zl.linkname]
                #        for zl in tf.getmembers() if zl.islnk() or zl.issym()}
                links = dict((, self.zones[zl.linkname])
                             for zl in tf.getmembers() if
                             zl.islnk() or zl.issym())
                    metadata_json = tf.extractfile(tf.getmember(METADATA_FN))
                    metadata_str ='UTF-8')
                    self.metadata = json.loads(metadata_str)
                except KeyError:
                    # no metadata in tar file
                    self.metadata = None
            self.zones = dict()
            self.metadata = None

# The current API has gettz as a module function, although in fact it taps into
# a stateful class. So as a workaround for now, without changing the API, we
# will create a new "global" class instance the first time a user requests a
# timezone. Ugly, but adheres to the api.
# TODO: deprecate this.

[docs]def gettz(name): if len(_CLASS_ZONE_INSTANCE) == 0: _CLASS_ZONE_INSTANCE.append(ZoneInfoFile(getzoneinfofile_stream())) return _CLASS_ZONE_INSTANCE[0].zones.get(name)
[docs]def gettz_db_metadata(): """ Get the zonefile metadata See `zonefile_metadata`_ :returns: A dictionary with the database metadata """ if len(_CLASS_ZONE_INSTANCE) == 0: _CLASS_ZONE_INSTANCE.append(ZoneInfoFile(getzoneinfofile_stream())) return _CLASS_ZONE_INSTANCE[0].metadata