| 1 | from __future__ import print_function # for OPy compiler
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| 2 | """Generic (shallow and deep) copying operations.
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| 3 |
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| 4 | Interface summary:
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| 5 |
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| 6 | import copy
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| 7 |
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| 8 | x = copy.copy(y) # make a shallow copy of y
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| 9 | x = copy.deepcopy(y) # make a deep copy of y
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| 10 |
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| 11 | For module specific errors, copy.Error is raised.
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| 12 |
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| 13 | The difference between shallow and deep copying is only relevant for
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| 14 | compound objects (objects that contain other objects, like lists or
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| 15 | class instances).
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| 16 |
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| 17 | - A shallow copy constructs a new compound object and then (to the
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| 18 | extent possible) inserts *the same objects* into it that the
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| 19 | original contains.
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| 20 |
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| 21 | - A deep copy constructs a new compound object and then, recursively,
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| 22 | inserts *copies* into it of the objects found in the original.
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| 23 |
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| 24 | Two problems often exist with deep copy operations that don't exist
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| 25 | with shallow copy operations:
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| 26 |
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| 27 | a) recursive objects (compound objects that, directly or indirectly,
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| 28 | contain a reference to themselves) may cause a recursive loop
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| 29 |
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| 30 | b) because deep copy copies *everything* it may copy too much, e.g.
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| 31 | administrative data structures that should be shared even between
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| 32 | copies
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| 33 |
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| 34 | Python's deep copy operation avoids these problems by:
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| 35 |
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| 36 | a) keeping a table of objects already copied during the current
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| 37 | copying pass
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| 38 |
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| 39 | b) letting user-defined classes override the copying operation or the
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| 40 | set of components copied
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| 41 |
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| 42 | This version does not copy types like module, class, function, method,
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| 43 | nor stack trace, stack frame, nor file, socket, window, nor array, nor
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| 44 | any similar types.
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| 45 |
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| 46 | Classes can use the same interfaces to control copying that they use
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| 47 | to control pickling: they can define methods called __getinitargs__(),
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| 48 | __getstate__() and __setstate__(). See the documentation for module
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| 49 | "pickle" for information on these methods.
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| 50 | """
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| 51 |
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| 52 | import types
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| 53 | import weakref
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| 54 | from copy_reg import dispatch_table
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| 55 |
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| 56 | class Error(Exception):
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| 57 | pass
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| 58 | error = Error # backward compatibility
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| 59 |
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| 60 | try:
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| 61 | from org.python.core import PyStringMap
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| 62 | except ImportError:
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| 63 | PyStringMap = None
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| 64 |
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| 65 | __all__ = ["Error", "copy", "deepcopy"]
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| 66 |
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| 67 | def copy(x):
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| 68 | """Shallow copy operation on arbitrary Python objects.
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| 69 |
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| 70 | See the module's __doc__ string for more info.
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| 71 | """
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| 72 |
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| 73 | cls = type(x)
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| 74 |
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| 75 | copier = _copy_dispatch.get(cls)
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| 76 | if copier:
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| 77 | return copier(x)
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| 78 |
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| 79 | copier = getattr(cls, "__copy__", None)
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| 80 | if copier:
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| 81 | return copier(x)
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| 82 |
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| 83 | reductor = dispatch_table.get(cls)
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| 84 | if reductor:
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| 85 | rv = reductor(x)
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| 86 | else:
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| 87 | reductor = getattr(x, "__reduce_ex__", None)
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| 88 | if reductor:
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| 89 | rv = reductor(2)
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| 90 | else:
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| 91 | reductor = getattr(x, "__reduce__", None)
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| 92 | if reductor:
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| 93 | rv = reductor()
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| 94 | else:
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| 95 | raise Error("un(shallow)copyable object of type %s" % cls)
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| 96 |
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| 97 | return _reconstruct(x, rv, 0)
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| 98 |
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| 99 |
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| 100 | _copy_dispatch = d = {}
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| 101 |
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| 102 | def _copy_immutable(x):
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| 103 | return x
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| 104 | for t in (type(None), int, long, float, bool, str, tuple,
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| 105 | frozenset, type, xrange, types.ClassType,
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| 106 | types.BuiltinFunctionType, type(Ellipsis),
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| 107 | types.FunctionType, weakref.ref):
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| 108 | d[t] = _copy_immutable
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| 109 | for name in ("ComplexType", "UnicodeType", "CodeType"):
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| 110 | t = getattr(types, name, None)
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| 111 | if t is not None:
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| 112 | d[t] = _copy_immutable
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| 113 |
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| 114 | def _copy_with_constructor(x):
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| 115 | return type(x)(x)
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| 116 | for t in (list, dict, set):
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| 117 | d[t] = _copy_with_constructor
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| 118 |
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| 119 | def _copy_with_copy_method(x):
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| 120 | return x.copy()
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| 121 | if PyStringMap is not None:
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| 122 | d[PyStringMap] = _copy_with_copy_method
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| 123 |
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| 124 | def _copy_inst(x):
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| 125 | if hasattr(x, '__copy__'):
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| 126 | return x.__copy__()
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| 127 | if hasattr(x, '__getinitargs__'):
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| 128 | args = x.__getinitargs__()
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| 129 | y = x.__class__(*args)
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| 130 | else:
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| 131 | y = _EmptyClass()
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| 132 | y.__class__ = x.__class__
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| 133 | if hasattr(x, '__getstate__'):
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| 134 | state = x.__getstate__()
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| 135 | else:
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| 136 | state = x.__dict__
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| 137 | if hasattr(y, '__setstate__'):
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| 138 | y.__setstate__(state)
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| 139 | else:
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| 140 | y.__dict__.update(state)
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| 141 | return y
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| 142 | d[types.InstanceType] = _copy_inst
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| 143 |
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| 144 | del d
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| 145 |
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| 146 | def deepcopy(x, memo=None, _nil=[]):
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| 147 | """Deep copy operation on arbitrary Python objects.
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| 148 |
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| 149 | See the module's __doc__ string for more info.
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| 150 | """
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| 151 |
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| 152 | if memo is None:
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| 153 | memo = {}
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| 154 |
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| 155 | d = id(x)
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| 156 | y = memo.get(d, _nil)
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| 157 | if y is not _nil:
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| 158 | return y
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| 159 |
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| 160 | cls = type(x)
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| 161 |
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| 162 | copier = _deepcopy_dispatch.get(cls)
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| 163 | if copier:
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| 164 | y = copier(x, memo)
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| 165 | else:
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| 166 | try:
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| 167 | issc = issubclass(cls, type)
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| 168 | except TypeError: # cls is not a class (old Boost; see SF #502085)
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| 169 | issc = 0
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| 170 | if issc:
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| 171 | y = _deepcopy_atomic(x, memo)
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| 172 | else:
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| 173 | copier = getattr(x, "__deepcopy__", None)
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| 174 | if copier:
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| 175 | y = copier(memo)
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| 176 | else:
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| 177 | reductor = dispatch_table.get(cls)
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| 178 | if reductor:
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| 179 | rv = reductor(x)
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| 180 | else:
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| 181 | reductor = getattr(x, "__reduce_ex__", None)
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| 182 | if reductor:
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| 183 | rv = reductor(2)
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| 184 | else:
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| 185 | reductor = getattr(x, "__reduce__", None)
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| 186 | if reductor:
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| 187 | rv = reductor()
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| 188 | else:
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| 189 | raise Error(
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| 190 | "un(deep)copyable object of type %s" % cls)
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| 191 | y = _reconstruct(x, rv, 1, memo)
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| 192 |
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| 193 | memo[d] = y
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| 194 | _keep_alive(x, memo) # Make sure x lives at least as long as d
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| 195 | return y
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| 196 |
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| 197 | _deepcopy_dispatch = d = {}
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| 198 |
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| 199 | def _deepcopy_atomic(x, memo):
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| 200 | return x
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| 201 | d[type(None)] = _deepcopy_atomic
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| 202 | d[type(Ellipsis)] = _deepcopy_atomic
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| 203 | d[int] = _deepcopy_atomic
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| 204 | d[long] = _deepcopy_atomic
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| 205 | d[float] = _deepcopy_atomic
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| 206 | d[bool] = _deepcopy_atomic
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| 207 | try:
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| 208 | d[complex] = _deepcopy_atomic
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| 209 | except NameError:
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| 210 | pass
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| 211 | d[str] = _deepcopy_atomic
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| 212 | try:
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| 213 | d[unicode] = _deepcopy_atomic
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| 214 | except NameError:
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| 215 | pass
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| 216 | try:
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| 217 | d[types.CodeType] = _deepcopy_atomic
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| 218 | except AttributeError:
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| 219 | pass
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| 220 | d[type] = _deepcopy_atomic
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| 221 | d[xrange] = _deepcopy_atomic
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| 222 | d[types.ClassType] = _deepcopy_atomic
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| 223 | d[types.BuiltinFunctionType] = _deepcopy_atomic
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| 224 | d[types.FunctionType] = _deepcopy_atomic
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| 225 | d[weakref.ref] = _deepcopy_atomic
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| 226 |
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| 227 | def _deepcopy_list(x, memo):
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| 228 | y = []
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| 229 | memo[id(x)] = y
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| 230 | for a in x:
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| 231 | y.append(deepcopy(a, memo))
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| 232 | return y
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| 233 | d[list] = _deepcopy_list
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| 234 |
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| 235 | def _deepcopy_tuple(x, memo):
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| 236 | y = []
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| 237 | for a in x:
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| 238 | y.append(deepcopy(a, memo))
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| 239 | d = id(x)
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| 240 | try:
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| 241 | return memo[d]
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| 242 | except KeyError:
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| 243 | pass
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| 244 | for i in range(len(x)):
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| 245 | if x[i] is not y[i]:
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| 246 | y = tuple(y)
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| 247 | break
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| 248 | else:
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| 249 | y = x
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| 250 | memo[d] = y
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| 251 | return y
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| 252 | d[tuple] = _deepcopy_tuple
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| 253 |
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| 254 | def _deepcopy_dict(x, memo):
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| 255 | y = {}
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| 256 | memo[id(x)] = y
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| 257 | for key, value in x.iteritems():
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| 258 | y[deepcopy(key, memo)] = deepcopy(value, memo)
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| 259 | return y
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| 260 | d[dict] = _deepcopy_dict
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| 261 | if PyStringMap is not None:
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| 262 | d[PyStringMap] = _deepcopy_dict
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| 263 |
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| 264 | def _deepcopy_method(x, memo): # Copy instance methods
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| 265 | return type(x)(x.im_func, deepcopy(x.im_self, memo), x.im_class)
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| 266 | _deepcopy_dispatch[types.MethodType] = _deepcopy_method
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| 267 |
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| 268 | def _keep_alive(x, memo):
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| 269 | """Keeps a reference to the object x in the memo.
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| 270 |
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| 271 | Because we remember objects by their id, we have
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| 272 | to assure that possibly temporary objects are kept
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| 273 | alive by referencing them.
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| 274 | We store a reference at the id of the memo, which should
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| 275 | normally not be used unless someone tries to deepcopy
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| 276 | the memo itself...
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| 277 | """
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| 278 | try:
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| 279 | memo[id(memo)].append(x)
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| 280 | except KeyError:
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| 281 | # aha, this is the first one :-)
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| 282 | memo[id(memo)]=[x]
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| 283 |
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| 284 | def _deepcopy_inst(x, memo):
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| 285 | if hasattr(x, '__deepcopy__'):
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| 286 | return x.__deepcopy__(memo)
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| 287 | if hasattr(x, '__getinitargs__'):
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| 288 | args = x.__getinitargs__()
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| 289 | args = deepcopy(args, memo)
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| 290 | y = x.__class__(*args)
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| 291 | else:
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| 292 | y = _EmptyClass()
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| 293 | y.__class__ = x.__class__
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| 294 | memo[id(x)] = y
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| 295 | if hasattr(x, '__getstate__'):
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| 296 | state = x.__getstate__()
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| 297 | else:
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| 298 | state = x.__dict__
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| 299 | state = deepcopy(state, memo)
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| 300 | if hasattr(y, '__setstate__'):
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| 301 | y.__setstate__(state)
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| 302 | else:
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| 303 | y.__dict__.update(state)
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| 304 | return y
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| 305 | d[types.InstanceType] = _deepcopy_inst
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| 306 |
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| 307 | def _reconstruct(x, info, deep, memo=None):
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| 308 | if isinstance(info, str):
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| 309 | return x
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| 310 | assert isinstance(info, tuple)
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| 311 | if memo is None:
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| 312 | memo = {}
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| 313 | n = len(info)
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| 314 | assert n in (2, 3, 4, 5)
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| 315 | callable, args = info[:2]
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| 316 | if n > 2:
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| 317 | state = info[2]
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| 318 | else:
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| 319 | state = None
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| 320 | if n > 3:
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| 321 | listiter = info[3]
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| 322 | else:
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| 323 | listiter = None
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| 324 | if n > 4:
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| 325 | dictiter = info[4]
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| 326 | else:
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| 327 | dictiter = None
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| 328 | if deep:
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| 329 | args = deepcopy(args, memo)
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| 330 | y = callable(*args)
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| 331 | memo[id(x)] = y
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| 332 |
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| 333 | if state is not None:
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| 334 | if deep:
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| 335 | state = deepcopy(state, memo)
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| 336 | if hasattr(y, '__setstate__'):
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| 337 | y.__setstate__(state)
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| 338 | else:
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| 339 | if isinstance(state, tuple) and len(state) == 2:
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| 340 | state, slotstate = state
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| 341 | else:
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| 342 | slotstate = None
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| 343 | if state is not None:
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| 344 | y.__dict__.update(state)
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| 345 | if slotstate is not None:
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| 346 | for key, value in slotstate.iteritems():
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| 347 | setattr(y, key, value)
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| 348 |
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| 349 | if listiter is not None:
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| 350 | for item in listiter:
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| 351 | if deep:
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| 352 | item = deepcopy(item, memo)
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| 353 | y.append(item)
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| 354 | if dictiter is not None:
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| 355 | for key, value in dictiter:
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| 356 | if deep:
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| 357 | key = deepcopy(key, memo)
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| 358 | value = deepcopy(value, memo)
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| 359 | y[key] = value
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| 360 | return y
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| 361 |
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| 362 | del d
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| 363 |
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| 364 | del types
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| 365 |
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| 366 | # Helper for instance creation without calling __init__
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| 367 | class _EmptyClass:
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| 368 | pass
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| 369 |
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| 370 | def _test():
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| 371 | l = [None, 1, 2L, 3.14, 'xyzzy', (1, 2L), [3.14, 'abc'],
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| 372 | {'abc': 'ABC'}, (), [], {}]
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| 373 | l1 = copy(l)
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| 374 | print(l1==l)
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| 375 | l1 = map(copy, l)
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| 376 | print(l1==l)
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| 377 | l1 = deepcopy(l)
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| 378 | print(l1==l)
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| 379 | class C:
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| 380 | def __init__(self, arg=None):
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| 381 | self.a = 1
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| 382 | self.arg = arg
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| 383 | if __name__ == '__main__':
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| 384 | import sys
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| 385 | file = sys.argv[0]
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| 386 | else:
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| 387 | file = __file__
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| 388 | self.fp = open(file)
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| 389 | self.fp.close()
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| 390 | def __getstate__(self):
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| 391 | return {'a': self.a, 'arg': self.arg}
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| 392 | def __setstate__(self, state):
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| 393 | for key, value in state.iteritems():
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| 394 | setattr(self, key, value)
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| 395 | def __deepcopy__(self, memo=None):
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| 396 | new = self.__class__(deepcopy(self.arg, memo))
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| 397 | new.a = self.a
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| 398 | return new
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| 399 | c = C('argument sketch')
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| 400 | l.append(c)
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| 401 | l2 = copy(l)
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| 402 | print(l == l2)
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| 403 | print(l)
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| 404 | print(l2)
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| 405 | l2 = deepcopy(l)
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| 406 | print(l == l2)
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| 407 | print(l)
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| 408 | print(l2)
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| 409 | l.append({l[1]: l, 'xyz': l[2]})
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| 410 | l3 = copy(l)
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| 411 | import repr
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| 412 | print(map(repr.repr, l))
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| 413 | print(map(repr.repr, l1))
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| 414 | print(map(repr.repr, l2))
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| 415 | print(map(repr.repr, l3))
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| 416 | l3 = deepcopy(l)
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| 417 | import repr
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| 418 | print(map(repr.repr, l))
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| 419 | print(map(repr.repr, l1))
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| 420 | print(map(repr.repr, l2))
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| 421 | print(map(repr.repr, l3))
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| 422 | class odict(dict):
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| 423 | def __init__(self, d = {}):
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| 424 | self.a = 99
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| 425 | dict.__init__(self, d)
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| 426 | def __setitem__(self, k, i):
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| 427 | dict.__setitem__(self, k, i)
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| 428 | self.a
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| 429 | o = odict({"A" : "B"})
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| 430 | x = deepcopy(o)
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| 431 | print((o, x))
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| 432 |
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| 433 | if __name__ == '__main__':
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| 434 | _test()
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