How do I find countries where the name has between 4 and 5 letters with regex in python list?

Question

How can I generate a list with regex in python for countries with 4 or 5 letters?

names = ['Azerbaijan', 'Zimbabwe', 'Cuba', 'Cambodia', 'Somalia','Mali', 'Belarus', "Côte d'Ivoire", 'Venezuela', 'Syria', 'Kazakhstan', 'Austria', 'Malawi', 'Romania', 'Congo (Brazzaville)']

I was trying to do this but it returns an empty list:

import re

n = [w for w in names if re.findall(r'[A-Z]{4,6},', str(names))]

print(n)

Output:
[]

It is an exercise that's why I can only do it with the module re. Any help will be appreciate.

Python has a native `len` function. – trincot Oct 23 '22 at 19:30 — trincot, Oct 23 '22 at 19:30

score 0 · Answer 1 · answered Oct 23 '22 at 19:33

0

if you need to use re then here is your answer find words of length 4 using regular expression

if you dont need to use re just do n = [name for name in names if len(name) in (4,5)]

answered Oct 23 '22 at 19:33

brownie

121
9

I'mahdi · Accepted Answer · 2022-10-24T11:39:00.743

0

You can use len(w).

>>> names = ['Azerbaijan', 'Zimbabwe', 'Cuba', 'Cambodia', 'Somalia','Mali', 'Belarus', "Côte d'Ivoire", 'Venezuela', 'Syria', 'Kazakhstan', 'Austria', 'Malawi', 'Romania', 'Congo (Brazzaville)']

>>> [w for w in names if w.isalpha() and (len(w) in range(4,6))]
['Cuba', 'Mali', 'Syria']

But if you want to solve it with regex you can use re.search and If maybe you have numbers in list you can use walrus operator (:=) for python >= 3.8

names = ['1234', 'Azerbaijan', 'Cuba']
print([w for w in names if (tmp := re.search(r'[A-Za-z]{4,5}', w)) and (tmp.group(0) == w)])
# ['Cuba']

For python < 3.8 you can use try/except.

names = ['1234', 'Azerbaijan', 'Cuba']

res = []
for w in names:
    try :
        if re.search(r'[A-Za-z]{4,5}', w).group(0) == w:
            res.append(w)
    except AttributeError:
        continue
print(res)
# ['Cuba']

edited Oct 24 '22 at 11:39

answered Oct 23 '22 at 19:33

I'mahdi

23,382
5
22
30

Why `range(4,5)` and not `[4,5]`? – knittl Oct 24 '22 at 09:10
@knittl, here you're right `[4,5]` is better, But how about `range(4,40)` or `[4,5,6,...37,38,39]` which is better, use `range` or use hard coding with `list`? – I'mahdi Oct 24 '22 at 11:08
I'd probably go for `len >= 4 and len <= 40` :) – knittl Oct 24 '22 at 11:12
@knittl, OK but I prefer to short this : `len >= 4 and len <= 40` to `len in range(4, 41)` ;) – I'mahdi Oct 24 '22 at 11:36
1

Thanks for fixing the off-by-one error with `range(4,5)`, which would only contain `4` :) – knittl Oct 24 '22 at 11:54

How do I find countries where the name has between 4 and 5 letters with regex in python list?

2 Answers2