This is relative. To me, as a beginner, it was useful to find out this library exists

That's because of this other line in your code:

print(sheep_count(array1))

Remove it or call the function with the right name: count_sheeps.

Traceback (most recent call last):
  File "tests.py", line 1, in <module>
    from solution import *
  File "/workspace/default/solution.py", line 11, in <module>
    print(sheep_count(array1))
NameError: name 'sheep_count' is not defined

It says line 11 and it shows the line's content in the error message.