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1 "Implementation of tzinfo classes for use with datetime.datetime." |
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2 |
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3 import time |
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4 from datetime import timedelta, tzinfo |
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5 from django.utils.encoding import smart_unicode, smart_str, DEFAULT_LOCALE_ENCODING |
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6 |
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7 class FixedOffset(tzinfo): |
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8 "Fixed offset in minutes east from UTC." |
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9 def __init__(self, offset): |
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10 if isinstance(offset, timedelta): |
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11 self.__offset = offset |
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12 offset = self.__offset.seconds // 60 |
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13 else: |
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14 self.__offset = timedelta(minutes=offset) |
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15 |
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16 sign = offset < 0 and '-' or '+' |
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17 self.__name = u"%s%02d%02d" % (sign, abs(offset) / 60., abs(offset) % 60) |
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18 |
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19 def __repr__(self): |
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20 return self.__name |
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21 |
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22 def utcoffset(self, dt): |
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23 return self.__offset |
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24 |
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25 def tzname(self, dt): |
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26 return self.__name |
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27 |
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28 def dst(self, dt): |
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29 return timedelta(0) |
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30 |
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31 class LocalTimezone(tzinfo): |
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32 "Proxy timezone information from time module." |
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33 def __init__(self, dt): |
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34 tzinfo.__init__(self) |
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35 self._tzname = self.tzname(dt) |
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36 |
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37 def __repr__(self): |
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38 return smart_str(self._tzname) |
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39 |
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40 def utcoffset(self, dt): |
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41 if self._isdst(dt): |
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42 return timedelta(seconds=-time.altzone) |
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43 else: |
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44 return timedelta(seconds=-time.timezone) |
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45 |
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46 def dst(self, dt): |
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47 if self._isdst(dt): |
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48 return timedelta(seconds=-time.altzone) - timedelta(seconds=-time.timezone) |
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49 else: |
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50 return timedelta(0) |
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51 |
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52 def tzname(self, dt): |
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53 try: |
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54 return smart_unicode(time.tzname[self._isdst(dt)], |
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55 DEFAULT_LOCALE_ENCODING) |
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56 except UnicodeDecodeError: |
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57 return None |
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58 |
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59 def _isdst(self, dt): |
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60 tt = (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.weekday(), 0, -1) |
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61 try: |
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62 stamp = time.mktime(tt) |
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63 except (OverflowError, ValueError): |
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64 # 32 bit systems can't handle dates after Jan 2038, and certain |
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65 # systems can't handle dates before ~1901-12-01: |
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66 # |
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67 # >>> time.mktime((1900, 1, 13, 0, 0, 0, 0, 0, 0)) |
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68 # OverflowError: mktime argument out of range |
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69 # >>> time.mktime((1850, 1, 13, 0, 0, 0, 0, 0, 0)) |
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70 # ValueError: year out of range |
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71 # |
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72 # In this case, we fake the date, because we only care about the |
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73 # DST flag. |
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74 tt = (2037,) + tt[1:] |
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75 stamp = time.mktime(tt) |
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76 tt = time.localtime(stamp) |
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77 return tt.tm_isdst > 0 |