Question

I have one reference list, such as :

dico = [ 'test', 'blabla' ]

And I would like to remove these items that are contains in an other list :

listTest = [ 'S01_test', 'S02_ahah', 'S03_blabla' ]

The result should be :

[ 'S02_ahah' ]

I try to use sets, but with no success. Any ideas ?

Thank you 🙂

Answer 1

You can do this with a list comprehension:

>>> [x for x in listTest if x.split('_')[1] not in dico]
['S02_ahah']

Or with filter():

>>> dico = [ 'test', 'blabla' ]
>>> listTest = [ 'S01_test', 'S02_ahah', 'S03_blabla' ]
>>> filter(lambda x: x.split('_')[1] not in dico, listTest)
['S02_ahah']

If you are on python-3.x remember to wrap filter() with list() since it returns an iterator:

>>> f = filter(lambda x: x.split('_')[1] not in dico, listTest)
>>> list(f)
['S02_ahah']

I would have probably prefer the use of filter() with a lambda over the list comprhension, but from a very basic timing the comprehension seems to be faster.