Python: Subset Elements In One List Based On Substring In Another List, Retain Only One Element Per Substring

I have two lists: list1 = ['abc-21-6/7', 'abc-56-9/10', 'def-89-7/3', 'hij-2-4/9', 'hij-75-1/7'] list2 = ['abc', 'hij'] I would like to subset list1 such that: 1) only those elem

Solution 1:

You can use itertools.groupby:

import itertools
importrandomlist1= ['abc-21-6/7', 'abc-56-9/10', 'def-89-7/3', 'hij-2-4/9', 'hij-75-1/7']

list2 = ['abc', 'hij']
new_list1 = [i for i in list1 ifany(b in i for b in list2)]
new_data = [list(b) for a, b in itertools.groupby(new_list1, key=lambda x: x.split("-")[0])]
final_data = [random.choice(i) for i in new_data]

Output:

['abc-56-9/10', 'hij-75-1/7']

Solution 2:

You can use the following function:

deffind(list1, findable):
    for element in list1:
        if findable in element:
            return element

Now we can use a list comprehension:

[find(list1, ele) for ele in list2 iffind(list1, ele) is not None]

This can be sped up without the list comprehension:

result = []
for ele in list2:
    found = find(list1, ele)
    if found isnotNone:
        result.append(found)

Solution 3:

You can use a dictionary instead of a list, and then convert the values to a list.

list1 = ['abc-21-6/7', 'abc-56-9/10', 'def-89-7/3', 'hij-2-4/9', 'hij-75-1/7']
list2 = ['abc', 'hij']

final_list = {pref:ele for pref in list2 for ele in list1 if pref in ele}
final_list = list(final_list.values())

this would output:

>>>final_list
['abc-56-9/10', 'hij-75-1/7']