Question

I have a nested list and another nested list which is a subset of the first list:

lst = [[1, 2], [3, 4], [1, 2], [5, 6], [8, 3], [2, 7]]
sublst = [[1, 2], [8, 3]]

How can I find the inner lists which are not in the sublist. The desired output using the above example is:

diff = [[3, 4], [5, 6], [2, 7]]

Answer 1

Use a list comprehension:

In [42]: lst = [[1, 2], [3, 4], [1, 2], [5, 6], [8, 3], [2, 7]]

In [43]: sublst = [[1, 2], [8, 3]]

In [44]: [x for x in lst if x not in sublst]
Out[44]: [[3, 4], [5, 6], [2, 7]]

or filter():

In [45]: filter(lambda x:x not in sublst,lst)
Out[45]: [[3, 4], [5, 6], [2, 7]]