>>> from nouformat import recodifica

>>> l = ['oax/z-2020','oux/n-2021','boua/n-2002','aux/z-2019']
>>> recodifica(l,'o')
>>> l
['OAX/Z G2', 'OUX/N G2', 'BOUA/N-2002', 'AUX/Z-2019']

>>> l = ['oax/z-2020','oux-n-2021','boua/n-2002','aux/z-2019']
>>> recodifica(l,'o')
>>> l
['OAX/Z G2', 'oux-n-2021*', 'BOUA/N-2002', 'AUX/Z-2019']

>>> l = ['oax/z-2020','oux/n-2021','boua/n-2002','aux/z-2019']
>>> recodifica(l,'x')
>>> l
['OAX/Z-2020', 'OUX/N-2021', 'BOUA/N-2002', 'AUX/Z-2019']

>>> l = []
>>> recodifica(l,'x')
>>> l
[]