partial match between two arrays in python

Question

I have two arrays:

a1 = ['a', 'b', 'c', 'd']
a2 = ['a_111', 'd_111']

how can I loop thorough array and do a partial match to find the difference is

['b', 'c']

and add 'b_111', 'c_111' to array a2?

Is there any particular way to do it in python? Thanks!

Answer 1

You can use a list comprehension/list.extend and all:

>>> a2 += [x + '_111' for x in a1 if all(x not in y for y in a2)]
>>> a2
['a_111', 'd_111', 'b_111', 'c_111']

or:

>>> a2.extend(x + '_111' for x in a1 if all(x not in y for y in a2))

If you want ['b', 'c'] as well, then you can break the above code into two steps:

>>> partial =  [x for x in a1 if all(x not in y for y in a2)]
>>> partial
['b', 'c']
>>> a2 += [x + '_111' for x in partial]
>>> a2
['a_111', 'd_111', 'b_111', 'c_111']