In Python, how should one extract the second-last

问题:

I have a string like the following:

/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore

How should I extract the "2.0.24" from this string? I'm not sure how to split the string using the slashes (in order to extract the second last element of the resultant list) and I'm not sure if this would be a good approach. What I have right now is the following:

"/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore".split("/RootCore")[0].split("AnalysisTop/")[1]

回答1:

'/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore'.split('/')[-2]

回答2:

You can also do:

import os
x = "/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore"
os.path.split(os.path.split(x)[0])[1]

results in

'2.0.24'

回答3:

Just split according to the / symbol then print the second index from the last.

>>> x = "/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore"
>>> y = x.split('/')
>>> y[-2]
'2.0.24'

回答4:

cross platform solution:

import os
'/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore'.split(os.path.sep)[-2]

回答5:

import re

str1 = "/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore"
t = re.findall("[0-9][.]*",str1)
print ("".join(t))

You can use regex-findall method. t returns a list, so using join().

Output;

>>> 
2.0.24
>>> 

# print (t)
>>> 
['2.', '0.', '2', '4']
>>> 

回答6:

path = "/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisTop/2.0.24/RootCore"
path_dirs = path.split("/")

>>>> path_dirs
>>>> ['', 'cvmfs', 'atlas.cern.ch', 'repo', 'sw', 'ASG', 'AnalysisTop', '2.0.24', 'RootCore']

>>>> print path_dirs[-2]
>>>> '2.0.24'