CODEWITHSUNDEEP
pythonlistsettypeerror
River Tam
River Tam

Reputation: 3216

Python TypeError: unhashable type: 'list'

I'm trying to run a program which is effectively doing the following:

if [4, 5, False, False, False, False] in {}

And, on this line, I'm getting a TypeError: unhashable type 'list'

What am I doing wrong?

Upvotes: 1

Views: 7139

Answers (3)

gerrit
gerrit

Reputation: 26435

The code if foo in {} checks if any of the keys of the dictionary is equal to foo.

In your example, foo is a list. A list is an unhashable type, and cannot be the key of a dictionary.

If you want to check if any entry of a list is contained in a dictionaries' keys or in a set, you can try:

if any([x in {} for x in (4, 5, False)]).

If you want to check if any of your values is equal to your list, you can try:

if any([v == [4, 5, False, False, False, False] for v in your_dict.values()])

Upvotes: 5

kamae
kamae

Reputation: 1867

A set holds hashable objects, which means that they are sortable and it enables efficient search/insert method. On the other hand a list is not hashable. That's why your code makes error. I recommend to use tuple instead of list.

if (4, 5, False, False, False, False) in {}:
  ...

Upvotes: 1

Yevgen Yampolskiy
Yevgen Yampolskiy

Reputation: 7180

You can do something like 

if all(x in {} for x in [4, 5, False, False, False, False]):
    ....

or 

if any(x in {} for x in [4, 5, False, False, False, False]):
    ....

depending on what you want

Upvotes: 0

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