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82 lines
2.2 KiB
Python
82 lines
2.2 KiB
Python
from datetime import datetime
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from sqlalchemy.types import TypeDecorator, TEXT
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import json
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import parsedatetime
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import functools
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class memoized(object):
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"""Decorator that caches a function's return value each time it is called.
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If called later with the same arguments, the cached value is returned, and
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not re-evaluated.
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"""
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def __init__(self, func):
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self.func = func
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self.cache = {}
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def __call__(self, *args):
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try:
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return self.cache[args]
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except KeyError:
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value = self.func(*args)
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self.cache[args] = value
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return value
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except TypeError:
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# uncachable -- for instance, passing a list as an argument.
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# Better to not cache than to blow up entirely.
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return self.func(*args)
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def __repr__(self):
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"""Return the function's docstring."""
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return self.func.__doc__
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def __get__(self, obj, objtype):
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"""Support instance methods."""
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return functools.partial(self.__call__, obj)
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def parse_human_datetime(s):
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"""
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Use the parsedatetime lib to return ``datetime.datetime`` from human
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generated strings
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>>> parse_human_datetime("now") <= datetime.now()
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True
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"""
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cal = parsedatetime.Calendar()
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return dttm_from_timtuple(cal.parse(s)[0])
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def dttm_from_timtuple(d):
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return datetime(
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d.tm_year, d.tm_mon, d.tm_mday, d.tm_hour, d.tm_min, d.tm_sec)
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def parse_human_timedelta(s):
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"""
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Use the parsedatetime lib to return ``datetime.datetime`` from human
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generated strings
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>>> parse_human_datetime("now") <= datetime.now()
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True
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"""
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cal = parsedatetime.Calendar()
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dttm = dttm_from_timtuple(datetime.now().timetuple())
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d = cal.parse(s, dttm)[0]
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d = datetime(
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d.tm_year, d.tm_mon, d.tm_mday, d.tm_hour, d.tm_min, d.tm_sec)
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return d - dttm
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class JSONEncodedDict(TypeDecorator):
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"""Represents an immutable structure as a json-encoded string."""
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impl = TEXT
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def process_bind_param(self, value, dialect):
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if value is not None:
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value = json.dumps(value)
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return value
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def process_result_value(self, value, dialect):
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if value is not None:
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value = json.loads(value)
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return value
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