I tried to use intertools in former katas and it seems it's not integred in Codewars and there's no console to install it, heh.

itertools is ought to be learnt:)

Oh my... yes. I really should have noticed that.
Thanks!

you're reading the test suite the wrong way around: this input expects 'Draw', not 'Red'. Meaning I guess you're reading the input of the test following the one that failed instead: the call to your function is done before the assertion, meaning the logs appears before the related assertion.

[python 3.6] I cannot make sense of some (~ 2-11) random tests failing.

For example:

# FAILED: 'Draw' should equal 'Red'

moves = ['G_Red', 'G_Yellow', 'B_Red', 'G_Yellow', 'G_Red',
         'B_Yellow', 'B_Red', 'G_Yellow', 'G_Red']

# ...which translates to this grid:
array([['.', '.', '.', '.', '.', '.', 'R'],
       ['.', '.', '.', '.', '.', '.', 'y'],
       ['.', '.', '.', '.', '.', '.', 'R'],
       ['.', 'R', '.', '.', '.', '.', 'y'],
       ['.', 'y', '.', '.', '.', '.', 'y'],
       ['.', 'R', '.', '.', '.', '.', 'R']], dtype=object)

The list of moves was aquired with

def who_is_winner(moves):
  print(moves)
  [...]

Yes? :')

O_O

Would have never thought of doing it like that. Thanks for that solution!

but inefficient. ;)

Ah, [:k] ... thats beautiful and so readable!

Zunks for zis!