How to strip everything but the first 2 characters for each item in a list?

Question

I'm using a list generated from from a directory containing multiple config files. All the config files follow the same naming convention, they start with two letters, followed by 2-3 numbers and end in .conf

aa01.conf, aa02.conf, aa03.conf, bb01.conf, bb02.conf,...zz99.conf, zz100.conf

I am only interested in the two letters at the start of the each file. How do I strip the numbers, the '.conf', and then remove all duplicates from the result?

Look at one of these https://stackoverflow.com/q/7961363/1741542, https://stackoverflow.com/q/480214/1741542 — Olaf Dietsche, Feb 06 '21 at 16:19
list(set([_[:2].strip() for _ in "aa01.conf, aa02.conf".split()])) — MatthewMartin, Feb 06 '21 at 16:20
Does this answer your question? [Removing duplicates in the lists](https://stackoverflow.com/questions/7961363/removing-duplicates-in-the-lists) — Tomerikoo, Feb 06 '21 at 16:44

score 0 · Accepted Answer · answered Feb 06 '21 at 16:20

0

If you only want the first two characters:

list_1 = ['aa01.conf', 'aa02.conf', 'aa03.conf', ... 'zz99.conf', 'zz100.conf']
list_2 = [item[:2] for item in list_1]

To remove the duplicates

list_3 = list(set(list_2))

answered Feb 06 '21 at 16:20

Peter Collingridge

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Thank you very much, I appreciate you taking the time to answer something so simple :) – Kirbus Feb 06 '21 at 16:32

score 0 · Answer 2 · answered Feb 06 '21 at 16:50

to have first two chars and extension, you can do something like this

your_list = ["aa01.conf", "aa02.conf", "aa03.conf", "bb01.conf", "bb02.conf"]

your_list_with_out_duplicates = list(set(your_list))
your_lis_of_first_two_char = [
    f"{x[:2]}.{x[-4:]}" for x in your_list_with_out_duplicates
]
print(your_lis_of_first_two_char)

output

['bb.conf', 'aa.conf', 'aa.conf', 'aa.conf', 'bb.conf']

How to strip everything but the first 2 characters for each item in a list?

2 Answers2