+ 9

How can regex find the middle three letters of a 5char-word?

Example findall(regex,"12345")=234 General case: find string w.o first and last.

2nd May 2020, 7:17 PM
Oma Falk
Oma Falk - avatar
13 Answers
+ 9
Oma Falk Based on the question: "How can regex find the middle 3 letters of a 5 char-word?" I'm assuming the word can include any non-whitespace alphanumeric character like this one: "12345" The regexes in this thread would work with this example. However, many may also incorrectly work for the following invalid values: " 234 " " 2345" "1234 " "1 3 5" "123 5" The same regexes may not properly extract "234" from 5 char values with leading and/or trailing whitespaces like the following: " 12345" "12345 " " 12345 " I believe the proper regex to cover all positive and negative test cases would be: re.search(r'(?<!\S)\S(\S{3})\S(?!\S)', s) - The \S matches on non whitespace characters. - (?https://code.sololearn.com/cnnrMYDDmP2x/ I hope this helps.
4th May 2020, 5:18 AM
David Carroll
David Carroll - avatar
+ 7
import re print(re.findall(r".(.{3}).", "12345")) print(re.findall(r".(.{3}).", "hello")) print(re.findall(r".(.{3}).", "12AA5")) same "pattern" used for all three.
2nd May 2020, 8:05 PM
rodwynnejones
rodwynnejones - avatar
+ 5
reg = re.compile(r'^(\d|\w)(\d{3}|\w{3})(\d|\w) ) mo = reg.search('12345') print(mo.group(2)) It works for letters or numbers. Not both
2nd May 2020, 7:32 PM
Slick
Slick - avatar
2nd May 2020, 8:00 PM
Oma Falk
Oma Falk - avatar
+ 4
Code Crasher want to learn regex. It is very mighty. After 3 hours I could find a regex for a String if it is a tictactoe winner. Hope to become a bit quicker.
2nd May 2020, 7:38 PM
Oma Falk
Oma Falk - avatar
+ 4
Ahhh groups...good.
2nd May 2020, 7:40 PM
Oma Falk
Oma Falk - avatar
+ 4
Code Crasher Yes...wehre else👍👍
2nd May 2020, 8:33 PM
Oma Falk
Oma Falk - avatar
+ 3
reg = r"\B.+\B" "The \B metacharacter is used to find a match, but where it is NOT at the beginning/end of a word." w3Schools.com
2nd May 2020, 11:57 PM
ODLNT
ODLNT - avatar
+ 3
Regex is such a lovely topic. You could use a lookaround pattern (lookbehind and lookahead), like: import re m=re.match(r"(?<=.).{3}(?=.)", your_5_chr_str).group() (since + and other special characters are greedy, you don't have to specify {3} though.) You could also capture it in a group: m=re.match(r".(.+).",your_5_chr_str).group(1)
3rd May 2020, 12:01 AM
Aymen
+ 2
This is what helped me get to grips with regular expression after the tutorial in Sololearn:- https://www.w3schools.com/python/python_regex.asp
2nd May 2020, 9:05 PM
rodwynnejones
rodwynnejones - avatar
+ 2
David Carroll yeeeees got it for 90%
4th May 2020, 6:01 AM
Oma Falk
Oma Falk - avatar
+ 1
Code Crasher brilliant
3rd May 2020, 12:05 AM
Aymen
+ 1
Folks... I need a regex for my feed post with state machine.
6th May 2020, 6:16 AM
Oma Falk
Oma Falk - avatar