dict.items()和之间是否有任何适用的差异dict.iteritems()？
从Python文档:
dict.items():返回字典的(键,值)对列表的副本.
dict.iteritems():在字典(键,值)对上返回一个迭代器.
如果我运行下面的代码,每个似乎都返回对同一对象的引用.我缺少哪些微妙的差异？
#!/usr/bin/python
d={1:'one',2:'two',3:'three'}
print 'd.items():'
for k,v in d.items():
if d[k] is v: print '\tthey are the same object'
else: print '\tthey are different'
print 'd.iteritems():'
for k,v in d.iteritems():
if d[k] is v: print '\tthey are the same object'
else: print '\tthey are different'
输出:
d.items():
they are the same object
they are the same object
they are the same object
d.iteritems():
they are the same …我想获取包含列表和字典的嵌套字典中所有键的列表。
我目前有这段代码，但似乎缺少向列表添加一些键，并且还重复添加了一些键。
keys_list = []
def get_keys(d_or_l, keys_list):
if isinstance(d_or_l, dict):
for k, v in iter(sorted(d_or_l.iteritems())):
if isinstance(v, list):
get_keys(v, keys_list)
elif isinstance(v, dict):
get_keys(v, keys_list)
else:
keys_list.append(k)
elif isinstance(d_or_l, list):
for i in d_or_l:
if isinstance(i, list):
get_keys(i, keys_list)
elif isinstance(i, dict):
get_keys(i, keys_list)
else:
print "** Skipping item of type: {}".format(type(d_or_l))
return keys_list
这仅需要一个空列表并用键填充它。d_or_l 是一个变量，并采用原始字典进行比较。