>>> from borsa import tendencia

>>> lborsa1 = [
...     ['ACME', 100, 102, 108, 103, 101, 99, 94, 98, 100],
...     ['NOVA', 50, 53, 57, 54, 52, 55, 60, 56, 54],
...     ['PLANA', 100, 101, 102, 103, 104, 105, 106, 107, 108]
... ]
>>> tendencia(lborsa1)
[('ACME', 'baixista'), ('NOVA', 'alcista'), ('PLANA', 'indefinida')]

>>> lborsa2 = [
...     ['BETA', 80, 77, 74, 78, 81, 79, 76, 82, 85],
...     ['OMEGA', 120, 118, 115, 117, 119, 116, 114, 118, 121],
...     ['SOLAR', 30, 32, 31, 35, 33, 36, 34, 38, 37]
... ]
>>> tendencia(lborsa2)
[('BETA', 'alcista'), ('OMEGA', 'baixista'), ('SOLAR', 'indefinida')]

>>> lborsa3 = [
...     ['MINA', 200, 198, 201, 197, 202, 196, 203, 195, 204],
...     ['MIXTA', 100, 105, 101, 107, 99, 108, 98, 106, 102]
... ]
>>> tendencia(lborsa3)
[('MINA', 'baixista'), ('MIXTA', 'alcista')]

>>> lborsa4 = [
...     ['ACME', 100, 102, 108, 103, 101, 99, 94, 98, 100],
...     ['BETA', 80, 77, 74, 78, 81, 79, 76, 82, 85],
...     ['SOLAR', 30, 32, 31, 35, 33, 36, 34, 38, 37],
...     ['PLANA', 100, 101, 102, 103, 104, 105, 106, 107, 108]
... ]
>>> tendencia(lborsa4)
[('ACME', 'baixista'), ('BETA', 'alcista'), ('SOLAR', 'indefinida'), ('PLANA', 'indefinida')]