How to get the extension of a filename from the path

[Lad]

Hello,
what is a way to get the the extension of a filename from the path?
E.g., on my XP windows the path can be
C:\Pictures\MyD ocs\test.txt
and I would like to get
the the extension of the filename, that is here
txt
I would like that to work on Linux also
Thank you for help
L.

[Dale Strickland-Clark]

Lad wrote:

Hello,
what is a way to get the the extension of a filename from the path?
E.g., on my XP windows the path can be
C:\Pictures\MyD ocs\test.txt
and I would like to get
the the extension of the filename, that is here
txt
I would like that to work on Linux also
Thank you for help
L.

Like this, you mean?

import os.path
os.path.splitex t("c:\\pictures \\mydocs\\test. txt")

('c:\\pictures\ \mydocs\\test', '.txt')

--
Dale Strickland-Clark
Riverhall Systems www.riverhall.co.uk

[Tom Anderson]

On Thu, 8 Dec 2005, Lad wrote:

what is a way to get the the extension of a filename from the path?
E.g., on my XP windows the path can be
C:\Pictures\MyD ocs\test.txt
and I would like to get
the the extension of the filename, that is here
txt
You want os.path.splitex t:

import os
os.path.splitex t("C:\Pictures\ MyDocs\test.txt ") ('C:\\Pictures\ \MyDocs\test', '.txt') os.path.splitex t("C:\Pictures\ MyDocs\test.txt ")[1] '.txt'

I would like that to work on Linux also

It'll be fine.

tom

--
[Philosophy] is kind of like being driven behind the sofa by Dr Who -
scary, but still entertaining. -- Itchyfidget

[Fredrik Lundh]

"Lad" <py****@hope.cz > wrote:

what is a way to get the the extension of a filename from the path?
E.g., on my XP windows the path can be
C:\Pictures\MyD ocs\test.txt
and I would like to get
the the extension of the filename, that is here
txt

I would like that to work on Linux also
Thank you for help

os.path.splitex t(filename) splits a filename into a name part (which may include
a path) and an extension part:

import os
f, e = os.path.splitex t(filename)

the extension will include the separator, so the following is always true:

assert f + e == filename

if you don't want the period, you can strip it off:

if e[:1] == ".":
e = e[1:]

but it's often easier to change your code to take the dot into account; instead
of

if e[:1] == ".":
e = e[1:]
if e == "txt":
handle_text_fil e(filename)
elif e in ("png", "jpg"):
handle_image_fi le(filename)

do

if e == ".txt":
handle_text_fil e(filename)
elif e in (".png", ".jpg"):
handle_image_fi le(filename)

on the other hand, for maximum portability, you can use

f, e = os.path.splitex t(filename)
if e.startswith(os .extsep):
e = e[len(os.extsep):]
if e == "txt":
...

but that's probably overkill...

</F>

[gene tani]

Lad wrote:

Hello,
what is a way to get the the extension of a filename from the path?
E.g., on my XP windows the path can be
C:\Pictures\MyD ocs\test.txt
and I would like to get
the the extension of the filename, that is here
txt
I would like that to work on Linux also
Thank you for help
L.

minor footnote: windows paths can be raw strings for os.path.split() ,
or you can escape "/"
tho Tom's examp indicates unescaped, non-raw string works with
splitext()

import os.path
# winpath='C:\\Pi ctures\\MyDocs\ \test.txt'
winpath=r'C:\Pi ctures\MyDocs\t est.txt'
fpath,fname_ext =os.path.split( winpath)
print "path: %s ;;;;; fname and ext: %s"%(fpath, fname_ext)
ext=fname_ext.s plit(".")[-1]
print ext

[Peter Hansen]

Fredrik Lundh wrote:

on the other hand, for maximum portability, you can use

f, e = os.path.splitex t(filename)
if e.startswith(os .extsep):
e = e[len(os.extsep):]
if e == "txt":
...

Is there ever a time when the original `e` could evaluate True, yet not
startswith(os.e xtsep)? In other words, could the first test be just

if e:
e = e[len(os.extsep):]

Also, note that for truly maximum portability one probably needs to add
to the code some knowledge of case-sensitivity and do a .lower() when
appropriate, as "txt" and "TXT" (and others) are equivalent on Windows
file systems. On that note, is there a common idiom for detecting that
information?

-Peter

[Lad]

Thank you ALL for help
Regards,
L.

[gene tani]

Lad wrote:

Thank you ALL for help
Regards,
L.

addendum: ASPN Python cookbook often has something relevant /
modifiable for your needs:

http://aspn.activestate.com/ASPN/Coo...n/Recipe/81931
http://aspn.activestate.com/ASPN/Coo...n/Recipe/52661

(in this case code from 2001 / 2 is probably py 2.0 or 2.1, shd still
work)

[Tom Anderson]

On Thu, 8 Dec 2005, gene tani wrote:

Lad wrote:

what is a way to get the the extension of a filename from the path?

minor footnote: windows paths can be raw strings for os.path.split() ,
or you can escape "/"
tho Tom's examp indicates unescaped, non-raw string works with
splitext()

DOH. Yes, my path's got a tab in it, hasn't it!

tom

--
Women are monsters, men are clueless, everyone fights and no-one ever
wins. -- cleanskies