Adds support for pytz tzinfo in instance() method

Author: sdispater

pendulum/pendulum.py

@@ -178,7 +178,7 @@ def __init__(self, year, month, day,
     @classmethod
     def instance(cls, dt, tz=UTC):
         """
-        Create a Carbon instance from a datetime one.
+        Create a Pendulum instance from a datetime one.
 
         :param dt: A datetime instance
         :type dt: datetime.datetime
@@ -190,6 +190,16 @@ def instance(cls, dt, tz=UTC):
         """
         tz = dt.tzinfo or tz
 
+        # Checking for pytz/tzinfo
+        if isinstance(tz, datetime.tzinfo) and not isinstance(tz, TimezoneInfo):
+            # pytz
+            if hasattr(tz, 'localize'):
+                tz = tz.zone
+            else:
+                # We have no sure way to figure out
+                # the timezone name, we raise an error
+                raise ValueError('Unsupported tzinfo [{}]'.format(tz))
+
         return cls(
             dt.year, dt.month, dt.day,
             dt.hour, dt.minute, dt.second, dt.microsecond,

tests/pendulum_tests/test_construct.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 import os
+import pytz
 from datetime import datetime
 from pendulum import Pendulum
 from pendulum.tz import timezone
@@ -115,6 +116,12 @@ def test_instance_timezone_aware_datetime(self):
         now = Pendulum.instance(datetime.now(TimezoneInfo.create(timezone('Europe/Paris'), 7200, True, 'EST')))
         self.assertEqual('Europe/Paris', now.timezone_name)
 
+    def test_instance_timezone_aware_datetime_pytz(self):
+        now = Pendulum.instance(
+            datetime.now(pytz.timezone('Europe/Paris'))
+        )
+        self.assertEqual('Europe/Paris', now.timezone_name)
+
     def test_now(self):
         now = Pendulum.now()
         in_paris = Pendulum.now('Europe/Paris')