import itertools
isolated_filenames = ['gdg36dhd3d_0.wav','gdg36dhd3d_1.wav','gdg36dhd3d_2.wav','344fikuo4q_0.wav','344fikuo4q_1.wav']
l = [(x.rsplit('_')[0], x.rsplit('_')[-1][:-4]) for x in isolated_filenames]
number_isolated_events = []
for k, g in itertools.groupby(l, key=lambda x: x[0]):
    number_isolated_events.append(tuple([k, len(list(g))])) # if you need to count group items
    #number_isolated_events.append(tuple([k, sum(int(z[1]) for z in g)])) # if you need to sum numeric suffixes
 
print(number_isolated_events)

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