select between lists elements with regex-CodePudding

I have 2 lists:

images = ['ND_row_id_4026.png',
          'ND_row_id_7693.png',
          'ND_row_id_5285.png',
          'ND_row_id_1045.png',
          'ND_row_id_2135.png',
          'ND_row_id_8155.png',
          'ND_row_id_3135.png']

masks = ['MA_row_id_4026.png',
         'MA_row_id_7693.png',
         'MA_row_id_5285.png',
         'MA_row_id_1045.png',
         'MA_row_id_2135.png']

I want to keep the masks files. So, I have 2 folders with images and masks and I want to keep all the masks that are in the masks list and the corresponding images. The images list is bigger than the masks.

So ,I want to keep from the images list:

images = ['ND_row_id_4026.png',
          'ND_row_id_7693.png',
          'ND_row_id_5285.png',
          'ND_row_id_1045.png',
          'ND_row_id_2135.png']

CodePudding user response：

It seems (based on your sample data) a simple list comprehension should suffice, just replacing the prefix for comparison:

res = [im for im in images if im.replace('ND', 'MA') in masks]

Output (for your sample data):

[
 'ND_row_id_4026.png',
 'ND_row_id_7693.png',
 'ND_row_id_5285.png',
 'ND_row_id_1045.png',
 'ND_row_id_2135.png'
]

If your lists are large, it would be more efficient to pre-process the masks array (as it is the smaller of the two):

m2 = [ma.replace('MA', 'ND') for ma in masks]
res = [im for im in images if im in m2]

CodePudding user response：

Try this

images = [image for image in images if image in [x.replace('MA','ND') for x in masks]]

Explanation:

[...]: make list

[image for image in images]: iterate along images list

... if image in [..]: filter the result and only return those who are in the other list.

[x.replace('MA','ND') for x in masks]: make list where MA is replaced by ND in mask