默认字典defaultdict
默认字典defaultdictdefaultdict是对字典的类型的补充，他默认给字典的值设置了一个类型。class defaultdict(dict): """ defaultdict(default_factory[, ...]) --> dict with default factory The default factory is called without arguments to produce a new value when a key is not present, in __getitem__ only. A defaultdict compares equal to a dict with the same items. All remaining arguments are treated the same as if they were passed to the dict constructor, including keyword arguments. """def copy(self): # real signature unknown; restored from __doc__ """ D.copy() -> a shallow copy of D. """ passdef __copy__(self, *args, **kwargs): # real signature unknown """ D.copy() -> a shallow copy of D. """ passdef __getattribute__(self, name): # real signature unknown; restored from __doc__ """ x.__getattribute__('name') <==> x.name """ passdef __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__ """ defaultdict(default_factory[, ...]) --> dict with default factory The default factory is called without arguments to produce a new value when a key is not present, in __getitem__ only. A defaultdict compares equal to a dict with the same items. All remaining arguments are treated the same as if they were passed to the dict constructor, including keyword arguments. # (copied from class doc) """ passdef __missing__(self, key): # real signature unknown; restored from __doc__ """ __missing__(key) # Called by __getitem__ for missing key; pseudo-code: if self.default_factory is None: raise KeyError((key,)) self[key] = value = self.default_factory() return value """ passdef __reduce__(self, *args, **kwargs): # real signature unknown """ Return state information for pickling. """ passdef __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ passdefault_factory = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""Factory for default value called by __missing__()."""原生字典：values = [11, 22, 33,44,55,66,77,88,99,90]my_dict = {}for value in values: if value>66: if my_dict.has_key('k1'): my_dict['k1'].append(value) else: my_dict['k1'] = [value] else: if my_dict.has_key('k2'): my_dict['k2'].append(value) else: my_dict['k2'] = [value]默认字典：from collections import defaultdictvalues = [11, 22, 33,44,55,66,77,88,99,90]my_dict = defaultdict(list)for value in values: if value>66: my_dict['k1'].append(value) else: my_dict['k2'].append(value)defaultdict字典解决方法