Expected type 'Iterable[SupportsLessThan | Any]' (matched generic type 'Iterable[SupportsLessThanT]'), got 'object' instead

Question

The two following blocks of code should be equivalent:

Block 1

array_1 = [[12, 15], [10, 1], [5, 13]]

print(array_1)
""" output:
[[12, 15], [10, 1], [5, 13]]
"""

print(sorted(array_1))
""" output:
[[5, 13], [10, 1], [12, 15]]
"""

---

Block 2

import numpy as np

np_array_1 = np.array([[12, 15], [10, 1], [5, 13]])

print(np_array_1)
""" output:
[[12 15]
 [10  1]
 [ 5 13]]
"""

array_1 = np_array_1.tolist()

print(array_1)
""" output:
[[12, 15], [10, 1], [5, 13]]
"""

print(sorted(array_1))
""" output:
[[5, 13], [10, 1], [12, 15]]
"""

---

But, in PyCharm, if I use:

sorted(np_array_1.tolist())  # SEE BLOCK 2

I receive this only warning, but apparently without any issue:

Expected type 'Iterable[SupportsLessThan | Any]' (matched generic type 'Iterable[SupportsLessThanT]'), got 'object' instead

I would like to get clean code, thank you.

Answer 1

This is a bug in PyCharm.

Please see:

https://youtrack.jetbrains.com/issue/PY-45958/Type-error-sorting-Iterable-of-dataclassorderTrue-instances