[Tut] Python TypeError: ‘dict_keys’ Not Subscriptable (Fix This Stupid Bug)

[Tut] Python TypeError: ‘dict_keys’ Not Subscriptable (Fix This Stupid Bug) - Printable Version

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[Tut] Python TypeError: ‘dict_keys’ Not Subscriptable (Fix This Stupid Bug) - xSicKxBot - 10-17-2022

Python TypeError: ‘dict_keys’ Not Subscriptable (Fix This Stupid Bug)

5/5 – (1 vote)

Do you encounter the following error message?

Code:
TypeError: 'dict_keys' object is not subscriptable

You’re not alone! This short tutorial will show you why this error occurs, how to fix it, and how to never make the same mistake again.

So, let’s get started!

Solution

Python raises the “

Code:
TypeError: 'dict_keys' object is not subscriptable

” if you use indexing or slicing on the

Code:
dict_keys

object obtained with

Code:
dict.keys()

. To solve the error, convert the

Code:
dict_keys

object to a list such as in

Code:
list(my_dict.keys())[0]

Code:
print(list(my_dict.keys())[0])

Example

The following minimal example that leads to the error:

Code:
d = {1:'a', 2:'b', 3:'c'}
print(d.keys()[0])

Output:

Code:
Traceback (most recent call last): File "C:\Users\...\code.py", line 2, in <module> print(d.keys()[0])
TypeError: 'dict_keys' object is not subscriptable

Note that the same error message occurs if you use slicing instead of indexing:

Code:
d = {1:'a', 2:'b', 3:'c'}
print(d.keys()[:-1]) # <== same error

Fixes

The reason this error occurs is that the

Code:
dictionary.keys()

method returns a

Code:
dict_keys

object that is not subscriptable.

You can use the

Code:
type()

function to check it for yourself:

Code:
print(type(d.keys()))
# <class 'dict_keys'>

Note: You cannot expect dictionary keys to be ordered, so using indexing on a non-ordered type wouldn’t make too much sense, would it?

You can fix the non-subscriptable TypeError by converting the non-indexable

Code:
dict_keys

object to an indexable container type such as a listin Python using the

Code:
list()

Code:
tuple()

function.

Here’s an example fix:

Code:
d = {1:'a', 2:'b', 3:'c'}
print(list(d.keys())[0])
# 1

Here’s an other example fix:

Code:
d = {1:'a', 2:'b', 3:'c'}
print(tuple(d.keys())[:-1])
# (1, 2)

Both lists and tuples are subscriptable so you can use indexing and slicing after converting the

Code:
dict_keys

object to a list or a tuple.

Full Guide: Python Fixing This Subsctiptable Error (General)

Summary

Python raises the

Code:
TypeError: 'dict_keys' object is not subscriptable

if you try to index

Code:
x[i]

or slice

Code:
x[i:j]

Code:
dict_keys

object.

The

Code:
dict_keys

type is not indexable, i.e., it doesn’t define the

Code:
__getitem__()

method. You can fix it by converting the dictionary keys to a list using the

Code:
list()

built-in function.

Alternatively, you can also fix this by removing the indexing or slicing call, or defining the

Code:
__getitem__

method. Although the previous approach is often better.

What’s Next?

I hope you’d be able to fix the bug in your code! Before you go, check out our free Python cheat sheets that’ll teach you the basics in Python in minimal time:

If you struggle with indexing in Python, have a look at the following articles on the Finxter blog—especially the third!