Switched to use Pendulum's C timezone implementation

CHANGELOG.md

@@ -21,6 +21,11 @@
 # Unreleased
 
 * Added Python 3.9 support
+* Switched to using a C implementation of `timezone` objects.
+    * Much faster parse times for timestamps with timezone information
+        * ~2.5x faster on Python 2.7, ~10% faster on Python 3.9
+    * Thanks to [`pendulum`](https://github.com/sdispater/pendulum) and @sdispater for the code.
+    * Python 2.7 users no longer need to install `pytz` dependency :smiley:
 
 # 2.x.x
 

MANIFEST.in

@@ -1,3 +1,4 @@
 include LICENSE
 include README.rst
 include CHANGELOG.md
+include timezone.h

README.rst

@@ -76,7 +76,7 @@ Parsing a timestamp with no time zone information (ex. ``2014-01-09T21:48:00``):
 
 .. <include:benchmark_with_no_time_zone.rst>
 
-.. table:: 
+.. table::
 
     +---------------+----------+----------+----------+----------+----------+-------------------------------+-----------------------------------------------+
     |    Module     |Python 3.8|Python 3.7|Python 3.6|Python 3.5|Python 3.4|          Python 2.7           |Relative Slowdown (versus ciso8601, Python 3.8)|
@@ -118,7 +118,7 @@ Parsing a timestamp with time zone information (ex. ``2014-01-09T21:48:00-05:30`
 
 .. <include:benchmark_with_time_zone.rst>
 
-.. table:: 
+.. table::
 
     +---------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+----------+-------------------------------+-----------------------------------------------+
     |    Module     |          Python 3.8           |          Python 3.7           |          Python 3.6           |          Python 3.5           |Python 3.4|          Python 2.7           |Relative Slowdown (versus ciso8601, Python 3.8)|
@@ -185,29 +185,6 @@ For full benchmarking details (or to run the benchmark yourself), see `benchmark
 
 .. _`benchmarking/README.rst`: https://github.com/closeio/ciso8601/blob/master/benchmarking/README.rst
 
-Dependency on pytz (Python 2)
------------------------------
-
-In Python 2, ``ciso8601`` uses the `pytz`_ library while parsing timestamps with time zone information. This means that if you wish to parse such timestamps, you must first install ``pytz``:
-
-.. _pytz: http://pytz.sourceforge.net/
-
-.. code:: python
-
-  pip install pytz
-
-Otherwise, ``ciso8601`` will raise an exception when you try to parse a timestamp with time zone information:
-
-.. code:: python
-
-  In [2]: ciso8601.parse_datetime('2014-12-05T12:30:45.123456-05:30')
-  Out[2]: ImportError: Cannot parse a timestamp with time zone information without the pytz dependency. Install it with `pip install pytz`.
-
-``pytz`` is intentionally not an explicit dependency of ``ciso8601``. This is because many users use ``ciso8601`` to parse only naive timestamps, and therefore don't need this extra dependency.
-In Python 3, ``ciso8601`` makes use of the built-in `datetime.timezone`_ class instead, so ``pytz`` is not necessary.
-
-.. _datetime.timezone: https://docs.python.org/3/library/datetime.html#timezone-objects
-
 Supported Subset of ISO 8601
 ----------------------------
 
@@ -227,11 +204,11 @@ The following date formats are supported:
    ``YYYY-MM-DD``                ``2018-04-29`` ✅
    ``YYYY-MM``                   ``2018-04``    ✅
    ``YYYYMMDD``                  ``2018-04``    ✅
-   ``--MM-DD`` (omitted year)    ``--04-29``    ❌              
+   ``--MM-DD`` (omitted year)    ``--04-29``    ❌
    ``--MMDD`` (omitted year)     ``--0429``     ❌
-   ``±YYYYY-MM`` (>4 digit year) ``+10000-04``  ❌   
-   ``+YYYY-MM`` (leading +)      ``+2018-04``   ❌   
-   ``-YYYY-MM`` (negative -)     ``-2018-04``   ❌   
+   ``±YYYYY-MM`` (>4 digit year) ``+10000-04``  ❌
+   ``+YYYY-MM`` (leading +)      ``+2018-04``   ❌
+   ``-YYYY-MM`` (negative -)     ``-2018-04``   ❌
    ============================= ============== ==================
 
 Week dates or ordinal dates are not currently supported.
@@ -247,7 +224,7 @@ Week dates or ordinal dates are not currently supported.
    ``YYYY-Www-D`` (week date)    ``2009-W01-1`` ❌
    ``YYYYWwwD`` (week date)      ``2009-W01-1`` ❌
    ``YYYY-DDD`` (ordinal date)   ``1981-095``   ❌
-   ``YYYYDDD`` (ordinal date)    ``1981095``    ❌ 
+   ``YYYYDDD`` (ordinal date)    ``1981095``    ❌
    ============================= ============== ==================
 
 Time Formats
@@ -264,22 +241,22 @@ The following time formats are supported:
 .. table::
    :widths: auto
 
-   =================================== =================== ==============  
-   Format                              Example             Supported          
-   =================================== =================== ============== 
-   ``hh``                              ``11``              ✅ 
-   ``hhmm``                            ``1130``            ✅ 
-   ``hh:mm``                           ``11:30``           ✅ 
-   ``hhmmss``                          ``113059``          ✅ 
-   ``hh:mm:ss``                        ``11:30:59``        ✅ 
-   ``hhmmss.ssssss``                   ``113059.123456``   ✅ 
-   ``hh:mm:ss.ssssss``                 ``11:30:59.123456`` ✅ 
-   ``hhmmss,ssssss``                   ``113059,123456``   ✅ 
-   ``hh:mm:ss,ssssss``                 ``11:30:59,123456`` ✅ 
-   Midnight (special case)             ``24:00:00``        ✅               
-   ``hh.hhh`` (fractional hours)       ``11.5``            ❌               
-   ``hh:mm.mmm`` (fractional minutes)  ``11:30.5``         ❌               
-   =================================== =================== ============== 
+   =================================== =================== ==============
+   Format                              Example             Supported
+   =================================== =================== ==============
+   ``hh``                              ``11``              ✅
+   ``hhmm``                            ``1130``            ✅
+   ``hh:mm``                           ``11:30``           ✅
+   ``hhmmss``                          ``113059``          ✅
+   ``hh:mm:ss``                        ``11:30:59``        ✅
+   ``hhmmss.ssssss``                   ``113059.123456``   ✅
+   ``hh:mm:ss.ssssss``                 ``11:30:59.123456`` ✅
+   ``hhmmss,ssssss``                   ``113059,123456``   ✅
+   ``hh:mm:ss,ssssss``                 ``11:30:59,123456`` ✅
+   Midnight (special case)             ``24:00:00``        ✅
+   ``hh.hhh`` (fractional hours)       ``11.5``            ❌
+   ``hh:mm.mmm`` (fractional minutes)  ``11:30.5``         ❌
+   =================================== =================== ==============
 
 **Note:** Python datetime objects only have microsecond precision (6 digits). Any additional precision will be truncated.
 
@@ -291,9 +268,9 @@ Time zone information may be provided in one of the following formats:
 .. table::
    :widths: auto
 
-   ========== ========== =========== 
-   Format     Example    Supported          
-   ========== ========== =========== 
+   ========== ========== ===========
+   Format     Example    Supported
+   ========== ========== ===========
    ``Z``      ``Z``      ✅
    ``z``      ``z``      ✅
    ``±hh``    ``+11``    ✅

module.c

@@ -1,21 +1,26 @@
 #include <Python.h>
 #include <ctype.h>
 #include <datetime.h>
+#include "timezone.h"
 
 #define STRINGIZE(x)            #x
 #define EXPAND_AND_STRINGIZE(x) STRINGIZE(x)
 
-#define PY_VERSION_AT_LEAST_32 \
-    ((PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 2) || PY_MAJOR_VERSION > 3)
 #define PY_VERSION_AT_LEAST_33 \
     ((PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 3) || PY_MAJOR_VERSION > 3)
 #define PY_VERSION_AT_LEAST_36 \
     ((PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 6) || PY_MAJOR_VERSION > 3)
 #define PY_VERSION_AT_LEAST_37 \
     ((PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 7) || PY_MAJOR_VERSION > 3)
 
-#if !PY_VERSION_AT_LEAST_37
-static PyObject *fixed_offset;
+// PyPy compatibility for cPython 3.7's Timezone API was added to PyPy 7.3.6
+// https://foss.heptapod.net/pypy/pypy/-/merge_requests/826
+#ifdef PYPY_VERSION
+    #define SUPPORTS_37_TIMEZONE_API \
+            (PYPY_VERSION_NUM >= 0x07030600)
+#else
+    #define SUPPORTS_37_TIMEZONE_API \
+            PY_VERSION_AT_LEAST_37
 #endif
 
 static PyObject *utc;
@@ -427,32 +432,34 @@ _parse(PyObject *self, PyObject *args, int parse_any_tzinfo, int rfc3339_only)
                 tzminute += 60 * tzhour;
                 tzminute *= tzsign;
 
-#if !PY_VERSION_AT_LEAST_32
-                if (fixed_offset == NULL || utc == NULL) {
-                    PyErr_SetString(PyExc_ImportError,
-                                    "Cannot parse a timestamp with time zone "
-                                    "information without the pytz dependency. "
-                                    "Install it with `pip install pytz`.");
-                    return NULL;
-                }
-#endif
-
                 if (tzminute == 0) {
                     tzinfo = utc;
                 }
-                else {
-#if PY_VERSION_AT_LEAST_37
-                    delta = PyDelta_FromDSU(0, 60 * tzminute, 0);
-                    tzinfo = PyTimeZone_FromOffset(delta);
+                else if (abs(tzminute) >= 1440) {
+                    /* Format the error message as if we were still using pytz
+                     * for Python 2 and datetime.timezone for Python 3.
+                     * This is done to maintain complete backwards
+                     * compatibility with ciso8601 2.0.x. Perhaps change to a
+                     * simpler message in ciso8601 v3.0.0.
+                     */
+#if PY_MAJOR_VERSION >= 3
+                    delta = PyDelta_FromDSU(0, tzminute * 60, 0);
+                    PyErr_Format(PyExc_ValueError,
+                                 "offset must be a timedelta"
+                                 " strictly between -timedelta(hours=24) and"
+                                 " timedelta(hours=24),"
+                                 " not %R.",
+                                 delta);
                     Py_DECREF(delta);
-#elif PY_VERSION_AT_LEAST_32
-                    tzinfo = PyObject_CallFunction(
-                        fixed_offset, "N",
-                        PyDelta_FromDSU(0, 60 * tzminute, 0));
 #else
-                    tzinfo =
-                        PyObject_CallFunction(fixed_offset, "i", tzminute);
+                    PyErr_Format(PyExc_ValueError,
+                                 "('absolute offset is too large', %d)",
+                                 tzminute);
 #endif
+                    return NULL;
+                }
+                else {
+                    tzinfo = new_fixed_offset(60 * tzminute);
                     if (tzinfo == NULL) /* ie. PyErr_Occurred() */
                         return NULL;
                 }
@@ -473,6 +480,8 @@ _parse(PyObject *self, PyObject *args, int parse_any_tzinfo, int rfc3339_only)
     /* Make sure that there is no more to parse. */
     if (*c != '\0') {
         PyErr_Format(PyExc_ValueError, "unconverted data remains: '%s'", c);
+        if (tzinfo != Py_None && tzinfo != utc)
+            Py_DECREF(tzinfo);
         return NULL;
     }
 
@@ -542,12 +551,6 @@ PyInit_ciso8601(void)
 initciso8601(void)
 #endif
 {
-#if !PY_VERSION_AT_LEAST_32
-    PyObject *pytz;
-#elif !PY_VERSION_AT_LEAST_37
-    PyObject *datetime;
-#endif
-
 #if PY_MAJOR_VERSION >= 3
     PyObject *module = PyModule_Create(&moduledef);
 #else
@@ -558,28 +561,23 @@ initciso8601(void)
                                EXPAND_AND_STRINGIZE(CISO8601_VERSION));
 
     PyDateTime_IMPORT;
-#if PY_VERSION_AT_LEAST_37
-    utc = PyDateTime_TimeZone_UTC;
-#elif PY_VERSION_AT_LEAST_32
-    datetime = PyImport_ImportModule("datetime");
-    if (datetime == NULL)
-        return NULL;
-    fixed_offset = PyObject_GetAttrString(datetime, "timezone");
-    if (fixed_offset == NULL)
-        return NULL;
-    utc = PyObject_GetAttrString(fixed_offset, "utc");
-    if (utc == NULL)
+
+    // PyMODINIT_FUNC is void in Python 2, returns PyObject* in Python 3
+    if (initialize_timezone_code(module) < 0) {
+#if PY_MAJOR_VERSION >= 3
         return NULL;
 #else
-    pytz = PyImport_ImportModule("pytz");
-    if (pytz == NULL) {
-        PyErr_Clear();
-    }
-    else {
-        fixed_offset = PyObject_GetAttrString(pytz, "FixedOffset");
-        utc = PyObject_GetAttrString(pytz, "UTC");
+        return;
+#endif
     }
+
+#if SUPPORTS_37_TIMEZONE_API
+    utc = PyDateTime_TimeZone_UTC;
+#else
+    utc = new_fixed_offset(0);
 #endif
+
+// PyMODINIT_FUNC is void in Python 2, returns PyObject* in Python 3
 #if PY_MAJOR_VERSION >= 3
     return module;
 #endif

setup.py

@@ -43,7 +43,7 @@
     ext_modules=[
         Extension(
             "ciso8601",
-            sources=["module.c"],
+            sources=["module.c", "timezone.c"],
             define_macros=[("CISO8601_VERSION", VERSION)],
         )
     ],

tests/test_timezone.py

@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+
+import sys
+
+from datetime import datetime, timedelta
+
+from ciso8601 import FixedOffset
+
+if sys.version_info.major == 2:
+    # We use unittest2 since it has a backport of the `unittest.TestCase.assertRaisesRegex` method,
+    # which is called `assertRaisesRegexp` in Python 2. This saves us the hassle of monkey-patching
+    # the class ourselves.
+    import unittest2 as unittest
+else:
+    import unittest
+
+
+class TimezoneTestCase(unittest.TestCase):
+    def test_utcoffset(self):
+        if sys.version_info >= (3, 2):
+            from datetime import timezone
+            for minutes in range(-1439, 1440):
+                td = timedelta(minutes=minutes)
+                tz = timezone(td)
+                built_in_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=tz)
+                our_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=FixedOffset(minutes * 60))
+                self.assertEqual(built_in_dt.utcoffset(), our_dt.utcoffset(), "`utcoffset` output did not match for offset: {minutes}".format(minutes=minutes))
+        else:
+            self.assertEqual(FixedOffset(0).utcoffset(), timedelta(minutes=0))
+            self.assertEqual(FixedOffset(+0).utcoffset(), timedelta(minutes=0))
+            self.assertEqual(FixedOffset(-0).utcoffset(), timedelta(minutes=0))
+            self.assertEqual(FixedOffset(-4980).utcoffset(), timedelta(hours=-1, minutes=-23))
+            self.assertEqual(FixedOffset(+45240).utcoffset(), timedelta(hours=12, minutes=34))
+
+    def test_dst(self):
+        if sys.version_info >= (3, 2):
+            from datetime import timezone
+            for minutes in range(-1439, 1440):
+                td = timedelta(minutes=minutes)
+                tz = timezone(td)
+                built_in_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=tz)
+                our_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=FixedOffset(minutes * 60))
+                self.assertEqual(built_in_dt.dst(), our_dt.dst(), "`dst` output did not match for offset: {minutes}".format(minutes=minutes))
+        else:
+            self.assertIsNone(FixedOffset(0).dst(), "UTC")
+            self.assertIsNone(FixedOffset(+0).dst(), "UTC")
+            self.assertIsNone(FixedOffset(-0).dst(), "UTC")
+            self.assertIsNone(FixedOffset(-4980).dst(), "UTC-01:23")
+            self.assertIsNone(FixedOffset(+45240).dst(), "UTC+12:34")
+
+    def test_tzname(self):
+        if sys.version_info >= (3, 2):
+            from datetime import timezone
+            for minutes in range(-1439, 1440):
+                td = timedelta(minutes=minutes)
+                tz = timezone(td)
+                built_in_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=tz)
+                our_dt = datetime(2014, 2, 3, 10, 35, 27, 234567, tzinfo=FixedOffset(minutes * 60))
+                self.assertEqual(built_in_dt.tzname(), our_dt.tzname(), "`tzname` output did not match for offset: {minutes}".format(minutes=minutes))
+        else:
+            self.assertEqual(FixedOffset(0).tzname(), "UTC+00:00")
+            self.assertEqual(FixedOffset(+0).tzname(), "UTC+00:00")
+            self.assertEqual(FixedOffset(-0).tzname(), "UTC+00:00")
+            self.assertEqual(FixedOffset(-4980).tzname(), "UTC-01:23")
+            self.assertEqual(FixedOffset(+45240).tzname(), "UTC+12:34")
+
+if __name__ == '__main__':
+    unittest.main()