问题
I'm looking for a simple method of identifying the last position of a string inside another string ... for instance. If I had: file = C:\Users\User\Desktop\go.py
and I wanted to crop this so that file = go.py
Normally I would have to run C:\Users\User\Desktop\go.py through a loop + find statement, and Evey time it encountered a \ it would ask ... is the the last \ in the string? ... Once I found the last \ I would then file = file[last\:len(file)]
I'm curious to know if there is a faster neater way to do this.. preferably without a loop.
Something like file = [file('\',last):len(file)]
If there is nothing like what I've shown above ... then can we place the loop inside the [:] somehow. Something like file = [for i in ...:len(file)]
thanks :)
回答1:
If it is only about file paths, you can use os.path.basename:
>>> import os
>>> os.path.basename(file)
'go.py'
Or if you are not running the code on Windows, you have to use ntpath instead of os.path.
回答2:
You could split the string into a list then get the last index of the list.
Sample:
>>> file = 'C:\Users\User\Desktop\go.py'
>>> print(file.split('\\')[-1])
go.py
回答3:
I agree with Felix on that file paths should be handled using os.path.basename. However, you might want to have a look at the built in string function rpartition.
>>> file = 'C:\Users\User\Desktop\go.py'
>>> before, separator, after = file.rpartition('\\')
>>> before
'C:\\Users\\User\\Desktop'
>>> separator
'\\'
>>> after
'go.py'
There's also the rfind function which gives you the last index of a substring.
>>> file.rfind('\\')
21
I realize that I'm a bit late to the party, but since this is one of the top results when searching for e.g. "find last in str python" on Google, I think it might help someone to add this information.
回答4:
For the general purpose case (as the OP said they like the generalisation of the split solution)...... try the rfind(str) function.
"myproject-version2.4.5.customext.zip".rfind(".")
edit: apologies, I hadn't realized how old this thread was... :-/
回答5:
For pathname manipulations you want to be using os.path.
For this specific problem you want to use the os.path.basename(path) function which will return the last component of a path, or an empty string if the path ends in a slash (ie. the path of a folder rather than a file).
import os.path
print os.path.basename("C:\Users\User\Desktop\go.py")
Gives:
go.py
来源：https://stackoverflow.com/questions/5686388/python-find-last-in-string