Dictionary keys match on list; get key/value pair

问题

In python... I have a list of elements 'my_list', and a dictionary 'my_dict' where some keys match in 'my_list'.

I would like to search the dictionary and retrieve key/value pairs for the keys matching the 'my_list' elements.

I tried this...

    if any(x in my_dict for x in my_list):
          print set(my_list)&set(my_dict)

But it doesn't do the job.

回答1:

(I renamed list to my_list and dict to my_dict to avoid the conflict with the type names.)

For better performance, you should iterate over the list and check for membership in the dictionary:

for k in my_list:
    if k in my_dict:
        print k, my_dict[k]

If you want to create a new dictionary from these key-value pairs, use

new_dict = {k: my_dict[k] for k in my_list if k in my_dict}

回答2:

Don't use dict and list as variable names. They shadow the built-in functions. Assuming list l and dictionary d:

kv = [(k, d[k]) for k in l if k in d]

回答3:

 new_dict = dict((k, v) for k, v in dict.iteritems() if k in list)

Turning list into a set set(list) may yield a noticeable speed increase

回答4:

What about print([kv for kv in dict.items() if kv[0] in list])

回答5:

Try This:

mydict = {'one': 1, 'two': 2, 'three': 3}
mykeys = ['three', 'one','ten']
newList={k:mydict[k] for k in mykeys if k in mydict}
print newList
{'three': 3, 'one': 1}

回答6:

Here is a one line solution for that

{i:my_dict[i] for i in set(my_dict.keys()).intersection(set(my_list))}

来源：https://stackoverflow.com/questions/6505008/dictionary-keys-match-on-list-get-key-value-pair