TypeError: unhashable type: 'list' in Python

Question

I am creating a dictionary and want list as key of my dictionary. For example:

aa[[45,2003]] =123, aa[[50,2013]] =143, etc.

But the above code gives error: "TypeError: unhashable type: 'list'". How can I use list as key of the dictionary?

Answer 1

From the error, you can understand that list is not allowed. Instead you can use tuple and reference the items in the tuple using index. Check the following example:

>>> aa={}
>>> aa[(45,2003)]=123
>>> aa[(50,2013)]=143
>>> for k,v in aa.items():
...     print(k[0],v)
...
(50, 143)
(45, 123)

Hope it helps.