TypeError in bisect when called with key argument

[michikoba]

Bug report

Bug description:

bisect functions raise TypeError when called with key argument.
Here is a minimum code to reproduce the issue:

import bisect
import operator

a = [('one', 1), ('two', 2)]
print(bisect.bisect(a, ('one', 1), key=operator.itemgetter(0)))

This results in the following error:

Traceback (most recent call last):
  File "/path/to/bisect_test.py", line 5, in <module>
    print(bisect.bisect(a, ('one', 1), key=operator.itemgetter(0)))
          ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'tuple' and 'str'

It seems that picking an item in a tuple has a problem.

CPython versions tested on:

3.12

Operating systems tested on:

macOS

[nineteendo]

You need to apply key() to the element:

key=operator.itemgetter(0)
print(bisect.bisect(a, key(('one', 1)), key=key))

[nineteendo]

See #20556 (comment)

[nineteendo]

@AlexWaygood, could you close this? This works as intended. Sorry for the ping.

[michikoba]

@nineteendo Thank you for your comment.
Now I understand that giving the field to be compared is better than the entire record in bisect search.