Improves adding/subtracting time performance.

Author: sdispater

pendulum/helpers.py

@@ -1,6 +1,111 @@
 # -*- coding: utf-8 -*-
 
+from math import copysign
+from datetime import timedelta
+
 try:
     from ._extensions._helpers import local_time
 except ImportError:
     from ._extensions.helpers import local_time
+
+from .constants import DAYS_PER_MONTHS
+
+
+def is_leap(year):
+    return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)
+
+
+def add_duration(dt, years=0, months=0, weeks=0, days=0,
+        hours=0, minutes=0, seconds=0, microseconds=0):
+    """
+    Adds a duration to a datetime instance.
+
+    :param dt: The datetime instance
+    :type dt: datetime.datetime
+
+    :param years: The number of years
+    :type years: int
+
+    :param months: The number of months
+    :type months: int
+
+    :param weeks: The number of weeks
+    :type weeks: int
+
+    :param days: The number of days
+    :type days: int
+
+    :param hours: The number of hours
+    :type hours: int
+
+    :param minutes: The number of minutes
+    :type minutes: int
+
+    :param seconds: The number of seconds
+    :type seconds: int
+
+    :param microseconds: The number of microseconds
+    :type microseconds: int
+
+    :rtype: datetime.datetime
+    """
+    days += weeks * 7
+
+    # Normalizing
+    if abs(microseconds) > 999999:
+        s = _sign(microseconds)
+        div, mod = divmod(microseconds * s, 1000000)
+        microseconds = mod * s
+        seconds += div * s
+
+    if abs(seconds) > 59:
+        s = _sign(seconds)
+        div, mod = divmod(seconds * s, 60)
+        seconds = mod * s
+        minutes += div * s
+
+    if abs(minutes) > 59:
+        s = _sign(minutes)
+        div, mod = divmod(minutes * s, 60)
+        minutes = mod * s
+        hours += div * s
+
+    if abs(hours) > 23:
+        s = _sign(hours)
+        div, mod = divmod(hours * s, 24)
+        hours = mod * s
+        days += div * s
+
+    if abs(months) > 11:
+        s = _sign(months)
+        div, mod = divmod(months * s, 12)
+        months = mod * s
+        years += div * s
+
+    year = dt.year + years
+    month = dt.month
+
+    if months:
+        month += months
+        if month > 12:
+            year += 1
+            month -= 12
+        elif month < 1:
+            year -= 1
+            month += 12
+
+    day = min(DAYS_PER_MONTHS[int(is_leap(year))][month], dt.day)
+
+    dt = dt.replace(year=year, month=month, day=day)
+
+    return dt + timedelta(
+        days=days,
+        hours=hours,
+        minutes=minutes,
+        seconds=seconds,
+        microseconds=microseconds
+    )
+
+
+def _sign(x):
+    return int(copysign(1, x))

pendulum/pendulum.py

@@ -5,15 +5,14 @@
 import calendar
 import datetime
 
-from dateutil.relativedelta import relativedelta
-
 from .date import Date
 from .time import Time
 from .period import Period
 from .exceptions import PendulumException
 from .tz import Timezone, UTC, FixedTimezone, local_timezone
 from .tz.timezone_info import TimezoneInfo
 from .parsing import parse
+from .helpers import add_duration
 from .constants import (
     YEARS_PER_CENTURY, YEARS_PER_DECADE,
     MONTHS_PER_YEAR,
@@ -1125,14 +1124,13 @@ def add(self, years=0, months=0, weeks=0, days=0,
 
         :rtype: Pendulum
         """
-        delta = relativedelta(
+        dt = add_duration(
+            self._datetime,
             years=years, months=months, weeks=weeks, days=days,
             hours=hours, minutes=minutes, seconds=seconds,
             microseconds=microseconds
         )
 
-        dt = self._datetime + delta
-
         if any([years, months, weeks, days]):
             # If we specified any of years, months, weeks or days
             # we will not apply the transition (if any)