| 1 | """A more or less complete user-defined wrapper around dictionary objects.""" |
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| 2 | |
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| 3 | class UserDict: |
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| 4 | def __init__(self, dict=None, **kwargs): |
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| 5 | self.data = {} |
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| 6 | if dict is not None: |
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| 7 | if not hasattr(dict,'keys'): |
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| 8 | dict = type({})(dict) # make mapping from a sequence |
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| 9 | self.update(dict) |
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| 10 | if len(kwargs): |
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| 11 | self.update(kwargs) |
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| 12 | def __repr__(self): return repr(self.data) |
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| 13 | def __cmp__(self, dict): |
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| 14 | if isinstance(dict, UserDict): |
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| 15 | return cmp(self.data, dict.data) |
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| 16 | else: |
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| 17 | return cmp(self.data, dict) |
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| 18 | def __len__(self): return len(self.data) |
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| 19 | def __getitem__(self, key): return self.data[key] |
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| 20 | def __setitem__(self, key, item): self.data[key] = item |
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| 21 | def __delitem__(self, key): del self.data[key] |
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| 22 | def clear(self): self.data.clear() |
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| 23 | def copy(self): |
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| 24 | if self.__class__ is UserDict: |
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| 25 | return UserDict(self.data) |
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| 26 | import copy |
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| 27 | data = self.data |
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| 28 | try: |
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| 29 | self.data = {} |
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| 30 | c = copy.copy(self) |
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| 31 | finally: |
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| 32 | self.data = data |
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| 33 | c.update(self) |
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| 34 | return c |
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| 35 | def keys(self): return self.data.keys() |
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| 36 | def items(self): return self.data.items() |
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| 37 | def iteritems(self): return self.data.iteritems() |
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| 38 | def iterkeys(self): return self.data.iterkeys() |
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| 39 | def itervalues(self): return self.data.itervalues() |
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| 40 | def values(self): return self.data.values() |
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| 41 | def has_key(self, key): return self.data.has_key(key) |
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| 42 | def update(self, dict): |
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| 43 | if isinstance(dict, UserDict): |
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| 44 | self.data.update(dict.data) |
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| 45 | elif isinstance(dict, type(self.data)): |
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| 46 | self.data.update(dict) |
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| 47 | else: |
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| 48 | for k, v in dict.items(): |
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| 49 | self[k] = v |
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| 50 | def get(self, key, failobj=None): |
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| 51 | if not self.has_key(key): |
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| 52 | return failobj |
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| 53 | return self[key] |
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| 54 | def setdefault(self, key, failobj=None): |
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| 55 | if not self.has_key(key): |
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| 56 | self[key] = failobj |
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| 57 | return self[key] |
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| 58 | def pop(self, key, *args): |
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| 59 | return self.data.pop(key, *args) |
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| 60 | def popitem(self): |
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| 61 | return self.data.popitem() |
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| 62 | def __contains__(self, key): |
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| 63 | return key in self.data |
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| 64 | def fromkeys(cls, iterable, value=None): |
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| 65 | d = cls() |
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| 66 | for key in iterable: |
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| 67 | d[key] = value |
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| 68 | return d |
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| 69 | fromkeys = classmethod(fromkeys) |
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| 70 | |
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| 71 | class IterableUserDict(UserDict): |
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| 72 | def __iter__(self): |
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| 73 | return iter(self.data) |
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| 74 | |
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| 75 | class DictMixin: |
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| 76 | # Mixin defining all dictionary methods for classes that already have |
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| 77 | # a minimum dictionary interface including getitem, setitem, delitem, |
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| 78 | # and keys. Without knowledge of the subclass constructor, the mixin |
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| 79 | # does not define __init__() or copy(). In addition to the four base |
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| 80 | # methods, progressively more efficiency comes with defining |
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| 81 | # __contains__(), __iter__(), and iteritems(). |
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| 82 | |
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| 83 | # second level definitions support higher levels |
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| 84 | def __iter__(self): |
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| 85 | for k in self.keys(): |
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| 86 | yield k |
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| 87 | def has_key(self, key): |
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| 88 | try: |
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| 89 | value = self[key] |
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| 90 | except KeyError: |
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| 91 | return False |
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| 92 | return True |
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| 93 | def __contains__(self, key): |
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| 94 | return self.has_key(key) |
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| 95 | |
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| 96 | # third level takes advantage of second level definitions |
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| 97 | def iteritems(self): |
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| 98 | for k in self: |
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| 99 | yield (k, self[k]) |
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| 100 | def iterkeys(self): |
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| 101 | return self.__iter__() |
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| 102 | |
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| 103 | # fourth level uses definitions from lower levels |
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| 104 | def itervalues(self): |
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| 105 | for _, v in self.iteritems(): |
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| 106 | yield v |
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| 107 | def values(self): |
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| 108 | return [v for _, v in self.iteritems()] |
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| 109 | def items(self): |
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| 110 | return list(self.iteritems()) |
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| 111 | def clear(self): |
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| 112 | for key in self.keys(): |
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| 113 | del self[key] |
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| 114 | def setdefault(self, key, default): |
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| 115 | try: |
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| 116 | return self[key] |
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| 117 | except KeyError: |
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| 118 | self[key] = default |
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| 119 | return default |
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| 120 | def pop(self, key, *args): |
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| 121 | if len(args) > 1: |
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| 122 | raise TypeError, "pop expected at most 2 arguments, got "\ |
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| 123 | + repr(1 + len(args)) |
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| 124 | try: |
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| 125 | value = self[key] |
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| 126 | except KeyError: |
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| 127 | if args: |
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| 128 | return args[0] |
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| 129 | raise |
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| 130 | del self[key] |
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| 131 | return value |
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| 132 | def popitem(self): |
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| 133 | try: |
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| 134 | k, v = self.iteritems().next() |
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| 135 | except StopIteration: |
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| 136 | raise KeyError, 'container is empty' |
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| 137 | del self[k] |
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| 138 | return (k, v) |
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| 139 | def update(self, other): |
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| 140 | # Make progressively weaker assumptions about "other" |
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| 141 | if hasattr(other, 'iteritems'): # iteritems saves memory and lookups |
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| 142 | for k, v in other.iteritems(): |
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| 143 | self[k] = v |
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| 144 | elif hasattr(other, '__iter__'): # iter saves memory |
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| 145 | for k in other: |
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| 146 | self[k] = other[k] |
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| 147 | else: |
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| 148 | for k in other.keys(): |
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| 149 | self[k] = other[k] |
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| 150 | def get(self, key, default=None): |
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| 151 | try: |
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| 152 | return self[key] |
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| 153 | except KeyError: |
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| 154 | return default |
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| 155 | def __repr__(self): |
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| 156 | return repr(dict(self.iteritems())) |
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| 157 | def __cmp__(self, other): |
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| 158 | if other is None: |
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| 159 | return 1 |
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| 160 | if isinstance(other, DictMixin): |
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| 161 | other = dict(other.iteritems()) |
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| 162 | return cmp(dict(self.iteritems()), other) |
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| 163 | def __len__(self): |
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| 164 | return len(self.keys()) |
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| 165 | |
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| 166 | def __nonzero__(self): |
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| 167 | return bool(self.iteritems()) |
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