>>> from trip_planner import calc_dist

--ini

>>> sol = calc_dist(0.0)
>>> sol
'error'

>>> sol = calc_dist(0.5)
>>> sol
'curta'

>>> sol = calc_dist(5.9)
>>> sol
'curta'

>>> sol = calc_dist(6.0)
>>> sol
'mitja'

--fi

>>> sol = calc_dist(99.99)
>>> sol
'mitja'

>>> sol = calc_dist(100.0)
>>> sol
'llarga'

>>> sol = calc_dist(1000.0)
>>> sol
'llarga'

>>> sol = calc_dist(0.0)
>>> sol
'error'

>>> sol = calc_dist(-1.0)
>>> sol
'error'