>>> from zona_de_cerca import distancia

>>> d = distancia(0, 0, 0, 1)
>>> round(d, 4)
1.0
>>> d = distancia(0, 0, -1, 0)
>>> round(d, 4)
1.0
>>> d = distancia(0, 0, 1, 1)
>>> round(d, 4)
1.4142
>>> d = distancia(7, 5, 4, 1)
>>> round(d, 4)
5.0
>>> d = distancia(-6, -5.78, 3, -4.27)
>>> round(d, 4)
9.1258