cpython/Lib/UserDict.py

142 lines
4.6 KiB
Python

"""A more or less complete user-defined wrapper around dictionary objects."""
class UserDict:
def __init__(self, dict=None):
self.data = {}
if dict is not None: self.update(dict)
def __repr__(self): return repr(self.data)
def __cmp__(self, dict):
if isinstance(dict, UserDict):
return cmp(self.data, dict.data)
else:
return cmp(self.data, dict)
def __len__(self): return len(self.data)
def __getitem__(self, key): return self.data[key]
def __setitem__(self, key, item): self.data[key] = item
def __delitem__(self, key): del self.data[key]
def clear(self): self.data.clear()
def copy(self):
if self.__class__ is UserDict:
return UserDict(self.data)
import copy
data = self.data
try:
self.data = {}
c = copy.copy(self)
finally:
self.data = data
c.update(self)
return c
def keys(self): return self.data.keys()
def items(self): return self.data.items()
def iteritems(self): return self.data.iteritems()
def iterkeys(self): return self.data.iterkeys()
def itervalues(self): return self.data.itervalues()
def values(self): return self.data.values()
def has_key(self, key): return self.data.has_key(key)
def update(self, dict):
if isinstance(dict, UserDict):
self.data.update(dict.data)
elif isinstance(dict, type(self.data)):
self.data.update(dict)
else:
for k, v in dict.items():
self[k] = v
def get(self, key, failobj=None):
if not self.has_key(key):
return failobj
return self[key]
def setdefault(self, key, failobj=None):
if not self.has_key(key):
self[key] = failobj
return self[key]
def pop(self, key):
return self.data.pop(key)
def popitem(self):
return self.data.popitem()
def __contains__(self, key):
return key in self.data
class IterableUserDict(UserDict):
def __iter__(self):
return iter(self.data)
class DictMixin:
# Mixin defining all dictionary methods for classes that already have
# a minimum dictionary interface including getitem, setitem, delitem,
# and keys. Without knowledge of the subclass constructor, the mixin
# does not define __init__() or copy(). In addition to the four base
# methods, progessively more efficiency comes with defining
# __contains__(), __iter__(), and iteritems().
# second level definitions support higher levels
def __iter__(self):
for k in self.keys():
yield k
def has_key(self, key):
try:
value = self[key]
except KeyError:
return False
return True
__contains__ = has_key
# third level takes advantage of second level definitions
def iteritems(self):
for k in self:
yield (k, self[k])
iterkeys = __iter__
# fourth level uses definitions from lower levels
def itervalues(self):
for _, v in self.iteritems():
yield v
def values(self):
return [v for _, v in self.iteritems()]
def items(self):
return list(self.iteritems())
def clear(self):
for key in self.keys():
del self[key]
def setdefault(self, key, default):
try:
return self[key]
except KeyError:
self[key] = default
return default
def pop(self, key):
value = self[key]
del self[key]
return value
def popitem(self):
try:
k, v = self.iteritems().next()
except StopIteration:
raise KeyError, 'container is empty'
del self[k]
return (k, v)
def update(self, other):
# Make progressively weaker assumptions about "other"
if hasattr(other, 'iteritems'): # iteritems saves memory and lookups
for k, v in other.iteritems():
self[k] = v
elif hasattr(other, '__iter__'): # iter saves memory
for k in other:
self[k] = other[k]
else:
for k in other.keys():
self[k] = other[k]
def get(self, key, default=None):
try:
return self[key]
except KeyError:
return default
def __repr__(self):
return repr(dict(self.iteritems()))
def __cmp__(self, other):
if isinstance(other, DictMixin):
other = dict(other.iteritems())
return cmp(dict(self.iteritems()), other)
def __len__(self):
return len(self.keys())