Suppose I have a String like gi|417072228|gb|JX515788.1|. I need to extract the digit part 417072228 out of it using python. How can I split that part from the string? Should I use regular expression?
Can anyone help me with this? Thanks in advance..
It looks like you have delimiters in your input string already, which makes this easy to do with the methods built in to the string data type. No need for regular expressions.
for segment in s.split('|'):
if segment.isdigit():
# do your stuff with the number
Use a list comprehension with re.match
>>> s = "gi|417072228|gb|JX515788.1|"
>>> [i for i in s.split('|') if re.match('^\d+$', i)]
['417072228']
>>> [i for i in s.split('|') if re.match('^\d+$', i)][0]
'417072228'
OR
>>> re.findall(r'(?:\||^)(\d+)(?:\||$)', s)
['417072228']
(?:\||^) Matches the start of a line anchor or | symbol.(\d+) Captures one or more digit characters.(?:\||$) Matches | symbol or end of the line anchor. re.findall function will give the first preference to capturing group then to the matches. So here, it would print only the characters which are present inside the group index 1.Seems like your input is a row from a CSV file, so if you just want the second column in each row you could do:
>>> row = 'gi|417072228|gb|JX515788.1|'
>>> row.split('|')[1]
'417072228'
Or to access all of the columns:
>>> columns = row.split('|')
>>> columns[0]
'gi'
>>> columns[1]
'417072228'
>>> columns[2]
'gb'
>>> columns[3]
'JX515788.1'
(?:^|(?<=\|))\d+(?=\||$)
You can simply use this with re.findall.See demo.
https://regex101.com/r/vD5iH9/44
import re
p = re.compile(r'(?:^|(?<=\|))\d+(?=\||$)', re.MULTILINE)
test_str = "gi|417072228|gb|JX515788.1|"
re.findall(p, test_str)
isdigitmethod.