Find the last substring after a character

Question

I know many ways how to find a substring: from start index to end index, between characters etc., but I have a problem which I don't know how to solve: I have a string like for example a path: folder1/folder2/folder3/new_folder/image.jpg and the second path: folder1/folder2/folder3/folder4/image2.png

And from this paths I want to take only the last parts: image.jpg and image2.png. How can I take a substring if I don't know when it starts (I don't know the index, but I can suppose that it will be after last / character), if many times one character repeats (/) and the extensions are different (.jpg and .png and even other)?

Answer 1

      import re
      pattern=re.compile(r"(.*?)/([a-zA-Z0-9]+?\.\w+)")
      y=pattern.match(x).groups()
      print y[1]

No length constraints.

Answer 2

you can do this split on last occurrence

my_string='folder1/folder2/folder3/new_folder/image2.png'
print(my_string.rsplit("/",1)[1])
output:-
image2.png

Answer 3

Use os.path.basename() instead and not worry about the details.

os.path.basename() returns the filename portion of your path:

>>> import os.path
>>> os.path.basename('folder1/folder2/folder3/new_folder/image.jpg')
'image.jpg'

For a more generic string splitting problem, you can use str.rpartition() to split a string on a given character sequence counting from the end:

>>> 'foo:bar:baz'.rpartition(':')
('foo:bar', ':', 'baz')
>>> 'foo:bar:baz'.rpartition(':')[-1]
'baz'

and with str.rsplit() you can split multiple times up to a limit, again from the end:

>>> 'foo:bar:baz:spam:eggs'.rsplit(':', 3)
['foo:bar', 'baz', 'spam', 'eggs']

Last but not least, you could use str.rfind() to find just the index of a substring, searching from the end:

>>> 'foo:bar:baz'.rfind(':')
7

Answer 4

You can do this as well -

str_mine = 'folder1/folder2/folder3/new_folder/image.jpg'    
print str_mine.split('/')[-1]

>> image.png