CODEWITHSUNDEEP
pythonpython-3.xlistdictionary
Juicy
Juicy

Reputation: 12500

Select values from a dictionary using a list of keys

How can I get values from a dictionary using the keys that are in a list?

For example, given a dictionary:

d = {
  'a': 1,
  'b': 2,
  'c': 3
}

and a list:

l = ['a', 'c']

I would like output:

1
3

Upvotes: 2

Views: 6844

Answers (4)

ggorlen
ggorlen

Reputation: 56855

You can use a list comprehension to select the values per key that exist in the dictionary:

>>> d = {
...     'a': 1,
...     'b': 2,
...     'c': 3,
... }
>>> L = ['a', 'c']
>>> result = [d[x] for x in L if x in d]
>>> result
[1, 3]
>>> for val in result:
...     print(val)
...
1
3

Upvotes: 1

Alex Taylor
Alex Taylor

Reputation: 8813

List comprehensions are very powerful at this sort of list manipulation:

print([d[x] for x in l])

Upvotes: 1

Raziel Ravenheart
Raziel Ravenheart

Reputation: 44

You can do something like this

print(d[l[0]])

or for more readability

idx = l[0]
print(d[idx])

You will need to loop every item to get all the values, and be sure the index exists.

If you want to check if a given key exists in the dictionary, you can do:

'a' in d

which will return True, or

'd' in d

will return False in your example. But either way, the value you are using will be coming from the indexed search in your list, or the variable you pass that value to.

idx in d

would return either False or True depending on the value stored in idx

Upvotes: 0

CSY
CSY

Reputation: 208

Here's the answer in for loop:

for j in l:
 print(d[j])

Upvotes: 1

Related Questions