> def flatten(x):
> for i in range(len(x)):
> if isinstance(x[i], list):
> x[i:i+1] = x[i]
I don't think this does what you want. Try [[[1,2,3]]] as a trivial
example.
A recursive version, that's not as short as yours:
def flatten(x):
"Recursive example to flatten a list"
if isinstance(x,list):
if len(x):
return flatten(x[0]) + flatten(x[1:])
return []
return [x]