(lst)
For an iterable of sub-iterables, generate each member of each
    sub-iterable in turn, i.e. a flattened version of that super-iterable.

    Example: Turn [[a,b,c],[d,e,f]] into [a,b,c,d,e,f].
For an iterable of sub-iterables, generate each member of each
    sub-iterable in turn, i.e. a flattened version of that super-iterable.
For an iterable of sub - iterables generate each member of each sub - iterable in turn i . e . a flattened version of that super - iterable .
def flatten(lst):
    """For an iterable of sub-iterables, generate each member of each
    sub-iterable in turn, i.e. a flattened version of that super-iterable.

    Example: Turn [[a,b,c],[d,e,f]] into [a,b,c,d,e,f].
    """
    for sublist in lst:
        for j in sublist:
            yield j
def flatten ( lst ) : for sublist in lst : for j in sublist : yield j