>>> from avio import Avio
>>> a = Avio('VU45X', 30)
>>> a.id
'VU45X'
>>> len(a)
30
>>> a[0, 'A'] = 'Pere'
>>> a[0, 'C'] = 'Lluís'
>>> a[29, 'F'] = 'Andrea'
>>> a[29, 'D'] = 'Jin'
>>> a[1, 'E']
'Lliure'
>>> a[29, 'D']
'Jin'
>>> a[0, 'A']
'Pere'
>>> try:
...    a[45, 'A']
... except:
...    print ("Error d'index")
Error d'index
>>> try:
...    a[3, 'M']
... except:
...    print ("Error d'index")
Error d'index