How to extract number from end of the string

Question

I have a string like "Titile Something/17". I need to cut out "/NNN" part which can be 3, 2, 1 digit number or may not be present.

How you do this in python? Thanks.

The deal is you show us what you've tried and code and how you'd approach the problem, SO is not a code writing service — EdChum, Mar 12 '15 at 09:26
@EdChum never thought about asking people write code for me, but a code sample - feedback is extremely helpful. — Croll, Mar 12 '15 at 09:40

Avinash Raj · Accepted Answer · 2015-03-12T09:31:56.407

3

\d{0,3} matches from zero upto three digits. $ asserts that we are at the end of a line.

re.search(r'/\d{0,3}$', st).group()

Example:

>>> re.search(r'/\d{0,3}$', 'Titile Something/17').group()
'/17'
>>> re.search(r'/\d{0,3}$', 'Titile Something/1').group()
'/1'

edited Mar 12 '15 at 09:31

answered Mar 12 '15 at 09:26

Avinash Raj

Nice, but not so readable :) **thefourtheye**'s sample better, how do you think? – Croll Mar 12 '15 at 09:32
@DmitrijA fourtheye's sample would work on `"Titile Something/foo"` input also. But i think you want the last part which has zero or upto three digits. – Avinash Raj Mar 12 '15 at 09:34
Yes you are correct here. But if there is no number, there is no slash also. For this i have to check result is not `None` before calling `.group()` on it. – Croll Mar 12 '15 at 09:39
i think you could easily check whether `re.search` returns a match object or not. – Avinash Raj Mar 12 '15 at 09:47

score 3 · Answer 2 · edited May 23 '17 at 12:12

You don't need RegEx here, simply use the built-in str.rindex function and slicing, like this

>>> data = "Titile Something/17"
>>> data[:data.rindex("/")]
'Titile Something'
>>> data[data.rindex("/") + 1:]
'17'

Or you can use str.rpartition, like this

>>> data.rpartition('/')[0]
'Titile Something'
>>> data.rpartition('/')[2]
'17'
>>>

Note: This will get any string after the last /. Use it with caution.

If you want to make sure that the split string is actually full of numbers, you can use str.isdigit function, like this

>>> data[data.rindex("/") + 1:].isdigit()
True
>>> data.rpartition('/')[2].isdigit()
True

score 2 · Answer 3 · answered Mar 12 '15 at 10:43

2

data = "Titile Something/17"

print data.split("/")[0]
'Titile Something' 
print data.split("/")[-1] #last part string after separator /
'17'

or

print data.split("/")[1] # next part after separator in this case this is the same
'17'

when You want add this to the list use strip() to remove newline "\n"

print data.split("/")[-1].strip()
'17'

~

answered Mar 12 '15 at 10:43

lunaferie

Thanks for input and welcome. But `split()` returns an array of items split by /, this not 100% matches my task. – Croll Mar 12 '15 at 10:44

vks · Answer 4 · 2015-03-12T09:34:04.180

1

I need to cut out "/NNN"

x = "Titile Something/17"
print re.sub(r"/.*$","",x)   #cuts the part after /
print re.sub(r"^.*?/","",x)  #cuts the part before /

Using re.sub you can what you want.

edited Mar 12 '15 at 09:34

answered Mar 12 '15 at 09:26

vks

4 Answers4