copy.py

python s60 1.4.5版本的源代码

# Portions Copyright (c) 2005 Nokia Corporation 
"""Generic (shallow and deep) copying operations."""

import types

class Error(Exception):
    pass
error = Error

try:
    from org.python.core import PyStringMap
except ImportError:
    PyStringMap = None

__all__ = ["Error", "error", "copy", "deepcopy"]

def copy(x):
    try:
        copierfunction = _copy_dispatch[type(x)]
    except KeyError:
        try:
            copier = x.__copy__
        except AttributeError:
            try:
                reductor = x.__reduce__
            except AttributeError:
                raise error, \
                      "un(shallow)copyable object of type %s" % type(x)
            else:
                y = _reconstruct(x, reductor(), 0)
        else:
            y = copier()
    else:
        y = copierfunction(x)
    return y

_copy_dispatch = d = {}

def _copy_atomic(x):
    return x
d[types.NoneType] = _copy_atomic
d[types.IntType] = _copy_atomic
d[types.LongType] = _copy_atomic
d[types.FloatType] = _copy_atomic
try:
    d[types.ComplexType] = _copy_atomic
except AttributeError:
    pass
d[types.StringType] = _copy_atomic
try:
    d[types.UnicodeType] = _copy_atomic
except AttributeError:
    pass
try:
    d[types.CodeType] = _copy_atomic
except AttributeError:
    pass
d[types.TypeType] = _copy_atomic
d[types.XRangeType] = _copy_atomic
d[types.ClassType] = _copy_atomic

def _copy_list(x):
    return x[:]
d[types.ListType] = _copy_list

def _copy_tuple(x):
    return x[:]
d[types.TupleType] = _copy_tuple

def _copy_dict(x):
    return x.copy()
d[types.DictionaryType] = _copy_dict
if PyStringMap is not None:
    d[PyStringMap] = _copy_dict

def _copy_inst(x):
    if hasattr(x, '__copy__'):
        return x.__copy__()
    if hasattr(x, '__getinitargs__'):
        args = x.__getinitargs__()
        y = apply(x.__class__, args)
    else:
        y = _EmptyClass()
        y.__class__ = x.__class__
    if hasattr(x, '__getstate__'):
        state = x.__getstate__()
    else:
        state = x.__dict__
    if hasattr(y, '__setstate__'):
        y.__setstate__(state)
    else:
        y.__dict__.update(state)
    return y
d[types.InstanceType] = _copy_inst

del d

def deepcopy(x, memo = None):
    if memo is None:
        memo = {}
    d = id(x)
    if memo.has_key(d):
        return memo[d]
    try:
        copierfunction = _deepcopy_dispatch[type(x)]
    except KeyError:
        try:
            issc = issubclass(type(x), type)
        except TypeError:
            issc = 0
        if issc:
            y = _deepcopy_dispatch[type](x, memo)
        else:
            try:
                copier = x.__deepcopy__
            except AttributeError:
                try:
                    reductor = x.__reduce__
                except AttributeError:
                    raise error, \
                       "un-deep-copyable object of type %s" % type(x)
                else:
                    y = _reconstruct(x, reductor(), 1, memo)
            else:
                y = copier(memo)
    else:
        y = copierfunction(x, memo)
    memo[d] = y
    _keep_alive(x, memo) # Make sure x lives at least as long as d
    return y

_deepcopy_dispatch = d = {}

def _deepcopy_atomic(x, memo):
    return x
d[types.NoneType] = _deepcopy_atomic
d[types.IntType] = _deepcopy_atomic
d[types.LongType] = _deepcopy_atomic
d[types.FloatType] = _deepcopy_atomic
try:
    d[types.ComplexType] = _deepcopy_atomic
except AttributeError:
    pass
d[types.StringType] = _deepcopy_atomic
try:
    d[types.UnicodeType] = _deepcopy_atomic
except AttributeError:
    pass
try:
    d[types.CodeType] = _deepcopy_atomic
except AttributeError:
    pass
d[types.TypeType] = _deepcopy_atomic
d[types.XRangeType] = _deepcopy_atomic

def _deepcopy_list(x, memo):
    y = []
    memo[id(x)] = y
    for a in x:
        y.append(deepcopy(a, memo))
    return y
d[types.ListType] = _deepcopy_list

def _deepcopy_tuple(x, memo):
    y = []
    for a in x:
        y.append(deepcopy(a, memo))
    d = id(x)
    try:
        return memo[d]
    except KeyError:
        pass
    for i in range(len(x)):
        if x[i] is not y[i]:
            y = tuple(y)
            break
    else:
        y = x
    memo[d] = y
    return y
d[types.TupleType] = _deepcopy_tuple

def _deepcopy_dict(x, memo):
    y = {}
    memo[id(x)] = y
    for key in x.keys():
        y[deepcopy(key, memo)] = deepcopy(x[key], memo)
    return y
d[types.DictionaryType] = _deepcopy_dict
if PyStringMap is not None:
    d[PyStringMap] = _deepcopy_dict

def _keep_alive(x, memo):
    try:
        memo[id(memo)].append(x)
    except KeyError:
        # aha, this is the first one :-)
        memo[id(memo)]=[x]

def _deepcopy_inst(x, memo):
    if hasattr(x, '__deepcopy__'):
        return x.__deepcopy__(memo)
    if hasattr(x, '__getinitargs__'):
        args = x.__getinitargs__()
        args = deepcopy(args, memo)
        y = apply(x.__class__, args)
    else:
        y = _EmptyClass()
        y.__class__ = x.__class__
    memo[id(x)] = y
    if hasattr(x, '__getstate__'):
        state = x.__getstate__()
    else:
        state = x.__dict__
    state = deepcopy(state, memo)
    if hasattr(y, '__setstate__'):
        y.__setstate__(state)
    else:
        y.__dict__.update(state)
    return y
d[types.InstanceType] = _deepcopy_inst

def _reconstruct(x, info, deep, memo=None):
    if isinstance(info, str):
        return x
    assert isinstance(info, tuple)
    if memo is None:
        memo = {}
    n = len(info)
    assert n in (2, 3)
    callable, args = info[:2]
    if n > 2:
        state = info[2]
    else:
        state = {}
    if deep:
        args = deepcopy(args, memo)
    y = callable(*args)
    if state:
        if deep:
            state = deepcopy(state, memo)
        if hasattr(y, '__setstate__'):
            y.__setstate__(state)
        else:
            y.__dict__.update(state)
    return y

del d

del types

# Helper for instance creation without calling __init__
class _EmptyClass:
    pass

def _test():
    l = [None, 1, 2L, 3.14, 'xyzzy', (1, 2L), [3.14, 'abc'],
         {'abc': 'ABC'}, (), [], {}]
    l1 = copy(l)
    print l1==l
    l1 = map(copy, l)
    print l1==l
    l1 = deepcopy(l)
    print l1==l
    class C:
        def __init__(self, arg=None):
            self.a = 1
            self.arg = arg
            if __name__ == '__main__':
                import sys
                file = sys.argv[0]
            else:
                file = __file__
            self.fp = open(file)
            self.fp.close()
        def __getstate__(self):
            return {'a': self.a, 'arg': self.arg}
        def __setstate__(self, state):
            for key in state.keys():
                setattr(self, key, state[key])
        def __deepcopy__(self, memo = None):
            new = self.__class__(deepcopy(self.arg, memo))
            new.a = self.a
            return new
    c = C('argument sketch')
    l.append(c)
    l2 = copy(l)
    print l == l2
    print l
    print l2
    l2 = deepcopy(l)
    print l == l2
    print l
    print l2
    l.append({l[1]: l, 'xyz': l[2]})
    l3 = copy(l)
    import repr
    print map(repr.repr, l)
    print map(repr.repr, l1)
    print map(repr.repr, l2)
    print map(repr.repr, l3)
    l3 = deepcopy(l)
    import repr
    print map(repr.repr, l)
    print map(repr.repr, l1)
    print map(repr.repr, l2)
    print map(repr.repr, l3)

if __name__ == '__main__':
    _test()