If it is all a list of lists, you could modify sir @Raymond's answer
L = [ [None], [123], [None], [151] ]
no_none_val = list(filter(None.__ne__, [x[0] for x in L] ) )
for python 2 however
no_none_val = [x[0] for x in L if x[0] is not None]
""" Both returns [123, 151]"""
<< list_indice[0] for variable in List if variable is not None >>