Update 2025-04-24_11:44:19

venv/lib/python3.11/site-packages/psycopg2/tz.py

@@ -0,0 +1,158 @@
+"""tzinfo implementations for psycopg2
+
+This module holds two different tzinfo implementations that can be used as
+the 'tzinfo' argument to datetime constructors, directly passed to psycopg
+functions or used to set the .tzinfo_factory attribute in cursors.
+"""
+# psycopg/tz.py - tzinfo implementation
+#
+# Copyright (C) 2003-2019 Federico Di Gregorio  <fog@debian.org>
+# Copyright (C) 2020-2021 The Psycopg Team
+#
+# psycopg2 is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# In addition, as a special exception, the copyright holders give
+# permission to link this program with the OpenSSL library (or with
+# modified versions of OpenSSL that use the same license as OpenSSL),
+# and distribute linked combinations including the two.
+#
+# You must obey the GNU Lesser General Public License in all respects for
+# all of the code used other than OpenSSL.
+#
+# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+# License for more details.
+
+import datetime
+import time
+
+ZERO = datetime.timedelta(0)
+
+
+class FixedOffsetTimezone(datetime.tzinfo):
+    """Fixed offset in minutes east from UTC.
+
+    This is exactly the implementation__ found in Python 2.3.x documentation,
+    with a small change to the `!__init__()` method to allow for pickling
+    and a default name in the form ``sHH:MM`` (``s`` is the sign.).
+
+    The implementation also caches instances. During creation, if a
+    FixedOffsetTimezone instance has previously been created with the same
+    offset and name that instance will be returned. This saves memory and
+    improves comparability.
+
+    .. versionchanged:: 2.9
+
+        The constructor can take either a timedelta or a number of minutes of
+        offset. Previously only minutes were supported.
+
+    .. __: https://docs.python.org/library/datetime.html
+    """
+    _name = None
+    _offset = ZERO
+
+    _cache = {}
+
+    def __init__(self, offset=None, name=None):
+        if offset is not None:
+            if not isinstance(offset, datetime.timedelta):
+                offset = datetime.timedelta(minutes=offset)
+            self._offset = offset
+        if name is not None:
+            self._name = name
+
+    def __new__(cls, offset=None, name=None):
+        """Return a suitable instance created earlier if it exists
+        """
+        key = (offset, name)
+        try:
+            return cls._cache[key]
+        except KeyError:
+            tz = super().__new__(cls, offset, name)
+            cls._cache[key] = tz
+            return tz
+
+    def __repr__(self):
+        return "psycopg2.tz.FixedOffsetTimezone(offset=%r, name=%r)" \
+            % (self._offset, self._name)
+
+    def __eq__(self, other):
+        if isinstance(other, FixedOffsetTimezone):
+            return self._offset == other._offset
+        else:
+            return NotImplemented
+
+    def __ne__(self, other):
+        if isinstance(other, FixedOffsetTimezone):
+            return self._offset != other._offset
+        else:
+            return NotImplemented
+
+    def __getinitargs__(self):
+        return self._offset, self._name
+
+    def utcoffset(self, dt):
+        return self._offset
+
+    def tzname(self, dt):
+        if self._name is not None:
+            return self._name
+
+        minutes, seconds = divmod(self._offset.total_seconds(), 60)
+        hours, minutes = divmod(minutes, 60)
+        rv = "%+03d" % hours
+        if minutes or seconds:
+            rv += ":%02d" % minutes
+            if seconds:
+                rv += ":%02d" % seconds
+
+        return rv
+
+    def dst(self, dt):
+        return ZERO
+
+
+STDOFFSET = datetime.timedelta(seconds=-time.timezone)
+if time.daylight:
+    DSTOFFSET = datetime.timedelta(seconds=-time.altzone)
+else:
+    DSTOFFSET = STDOFFSET
+DSTDIFF = DSTOFFSET - STDOFFSET
+
+
+class LocalTimezone(datetime.tzinfo):
+    """Platform idea of local timezone.
+
+    This is the exact implementation from the Python 2.3 documentation.
+    """
+    def utcoffset(self, dt):
+        if self._isdst(dt):
+            return DSTOFFSET
+        else:
+            return STDOFFSET
+
+    def dst(self, dt):
+        if self._isdst(dt):
+            return DSTDIFF
+        else:
+            return ZERO
+
+    def tzname(self, dt):
+        return time.tzname[self._isdst(dt)]
+
+    def _isdst(self, dt):
+        tt = (dt.year, dt.month, dt.day,
+              dt.hour, dt.minute, dt.second,
+              dt.weekday(), 0, -1)
+        stamp = time.mktime(tt)
+        tt = time.localtime(stamp)
+        return tt.tm_isdst > 0
+
+
+LOCAL = LocalTimezone()
+
+# TODO: pre-generate some interesting time zones?