Add item to list if not already exists

Question

I'm new to Python and got following problem:

a = [[0,abc,1],[0,def,1]]

b = [abc,jkl]

Output should be:

c = [[0,abc,1],[0,def,1],[0,jkl,1]]

Can anyone help me out there?

Answer 1

It can be done with the following code:

In [3]: a = [[0,'abc',1],[0,'def',1]]
In [4]: b = ['abc','jkl']
In [5]: c = a[:]
In [6]: c.extend([[0,e,1] for e in b if e not in [x for _,x,_ in a]])
In [7]: c
Out[8]: [[0, 'abc', 1], [0, 'def', 1], [0, 'jkl', 1]]

Hope this helps!