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@aaronchall
Last active August 29, 2015 14:27
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typed lists
from datetime import datetime, date
from decimal import Decimal
class TypedList(list):
'''assumes subclassed with attribute _type constructor'''
@classmethod
def gen_type(cls, iterable):
return (cls._type(i) for i in iterable)
def __init__(self, iterable=()):
super(TypedList, self).__init__(self.gen_type(iterable))
def insert(self, index, object):
super(TypedList, self).insert(index, self._type(object))
def extend(self, iterable):
super(TypedList, self).extend(self.gen_type(iterable))
def __iadd__(self, other):
return super(TypedList, self).__iadd__(self.gen_type(other))
def append(self, object):
super(TypedList, self).append(self._type(object))
def __setslice__(self, i, j, sequence):
super(TypedList, self).__setitem__(self, i, j, self.gen_type(sequence))
def __setitem__(self, key, value):
super(TypedList, self).__setitem__(key, self._type(value))
# 'string[]'
class StrList(TypedList):
_type = str
# 'float[]'
class FloatList(TypedList):
_type = float
# 'int[]'
class IntList(TypedList):
_type = int
# 'decimal[]' # ???
class DecimalList(TypedList):
'''must convert floats to strings before giving to list'''
_type = Decimal
# 'date[]'
class DateList(TypedList):
'''can convert from date 3-tuple'''
@staticmethod
def _type(obj):
if isinstance(obj, date):
return obj
if isinstance(obj, datetime):
return obj.date
return date(*obj)
# 'time[]'
class TimeList(TypedList):
'''can convert from timetuple, i.e. 3+tuple'''
@staticmethod
def _type(obj):
if isinstance(obj, datetime):
return obj
if isinstance(obj, date):
return datetime(*obj.timetuple()[:6])
if isinstance(obj, (int, long)):
return datetime.fromtimestamp(obj)
return datetime(*obj)
sl = StrList('0123')
print(sl)
il = IntList(sl)
print(il)
fl = FloatList(il)
print(fl)
dl = DecimalList(sl)
dl += il
print(dl)
datel = DateList()
datel.append(date.today())
datel.extend(((1,1,1),(2,2,2)))
print(datel)
timel = TimeList(datel)
timel.append(datetime.now())
print(timel)
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