我想做的事情是:

foo = {
    'foo': 1,
    'zip': 2,
    'zam': 3,
    'bar': 4
}

if ("foo", "bar") in foo:
    #do stuff

我如何检查是否foo和酒吧都在dict foo?


当前回答

我认为这是最聪明和最精辟的。

{'key1','key2'} <= my_dict.keys()

其他回答

使用集:

if set(("foo", "bar")).issubset(foo):
    #do stuff

另外:

if set(("foo", "bar")) <= set(foo):
    #do stuff
if {"foo", "bar"} <= myDict.keys(): ...

如果你还在使用python2,你可以这样做

if {"foo", "bar"} <= myDict.viewkeys(): ...

如果你仍然使用非常老的Python <= 2.6,你可以在字典上调用set,但它会遍历整个字典来构建集合,这是很慢的:

if set(("foo", "bar")) <= set(myDict): ...
my_dict = {
    'name': 'Askavy',
    'country': 'India',
    'age': 30
}

if set(('name', 'country','age')).issubset(my_dict.keys()):
     print("All keys are present in the dictionary") 
else: 
    print("All keys are not present in  the dictionary") 

那么使用呢?

 if reduce( (lambda x, y: x and foo.has_key(y) ), [ True, "foo", "bar"] ): # do stuff

简单的基准测试钻机3的替代品。

输入D和Q的值


>>> from timeit import Timer
>>> setup='''from random import randint as R;d=dict((str(R(0,1000000)),R(0,1000000)) for i in range(D));q=dict((str(R(0,1000000)),R(0,1000000)) for i in range(Q));print("looking for %s items in %s"%(len(q),len(d)))'''

>>> Timer('set(q) <= set(d)','D=1000000;Q=100;'+setup).timeit(1)
looking for 100 items in 632499
0.28672504425048828

#This one only works for Python3
>>> Timer('set(q) <= d.keys()','D=1000000;Q=100;'+setup).timeit(1)
looking for 100 items in 632084
2.5987625122070312e-05

>>> Timer('all(k in d for k in q)','D=1000000;Q=100;'+setup).timeit(1)
looking for 100 items in 632219
1.1920928955078125e-05