Question

I am having a bit of trouble putting this logic on paper:

The string I would like to parse: "Jan - 2012 Presentation v1.3.ppt.pdf - 500KB"
This string can vary but the structure is always “NAME+EXT+FILESIZE”

I want to return the extension. However for obvious reasons I cannot just split(".")
So I came up with something else:

stringy = "Jan - 2012 Presentation v1.3.ppt.pdf - 500KB"
ext = [".pdf",".jpg",".ppt",".txt",".doc"]

for i in ext:
    indx = stringy.find(i)
    ...

I got stuck where I need to figure out how to tell Python to take the extension starting with the biggest index yielded. Should be something like whatiwant = stringy[indx:4], but I can’t figure out how to tell it to only take the largest index… The largest index will obviously mean the last extension in the string, which is the one I want to get. In this particular example, I don’t care about “ppt”, but rather the “pdf”.

Can this perhaps be done in a more pythonic way? Or at least more efficiently?

Answer 1

In [44]: stringy[stringy.rfind('.'):stringy.rfind('.')+4]
Out[44]: '.pdf'