looping through specific files in python

Question

So I have a script where I loops through a set of files in a folder. After retrieving the list of files in that particular directory, how do I specify which files I want to use in the script?

target = './directory/'

for file in listdir(target):

Now I have several different files in the same folder.

kplr006933899-2009131105131_llc.fits
kplr006933899-2009131105131_lpd-targ.fits
kplr006933899-2012151031540_slc.fits
kplr006933899-2012151031540_spd-targ.fits

They all are part of the same group, which is denoted by "kplr006933899". How can I specify parts of the strings as different variable in order to specify which files I want to loop through?

Like for example:

def function(name,types)

where you could write when called:

function(kplr006933899,[slc,llc])

Could you explain better? I mean, you want to group together all the files that start with kplr + some number and that contain specific other substrings or you simply want to filter the names that start with kplr and contain some substring? — Bakuriu
– Bakuriu, Commented Feb 3, 2013 at 20:19

Simeon Visser · Accepted Answer · 2013-02-03 20:25:14Z

3

There are multiple ways of doing this. First way:

import fnmatch

def my_function(name, types):
    result = []
    for t in types:
        pattern = "{}*{}.fits".format(name, t)
        for filename in fnmatch.filter(listdir(target), pattern):
            result.append(filename)
    return result

You can call this function with: my_function("kplr006933899", ["slc", "llc"]). The fnmatch.filter function performs the pattern matching with your pattern and the given filenames.

The second way is to use glob:

result = []
for t in types:
    result.extend(glob.glob("{}/{}*{}.fits".format(target, name, t)))
return result

edited Feb 3, 2013 at 20:25

answered Feb 3, 2013 at 20:19

Simeon Visser

123k19 gold badges192 silver badges185 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Simeon Visser Over a year ago

@Bakuriu: Thanks, makes sense. I've added the glob solution as well.

Timur Cetindag Over a year ago

Thank you simeon! This is perfect!

ev-br · Accepted Answer · 2013-02-03 20:14:10Z

0

>>> "kplr" in  "kplr006933899-2009131105131_llc.fits"
True
>>> 
>>> "kplR" in  "kplr006933899-2009131105131_llc.fits"
False
>>>

Notice that you need to put quotes to denote a string function("kplr006933899", [slc, llc]), otherwise kplr006933899 will be interpreted as a variable.

answered Feb 3, 2013 at 20:14

ev-br

26.3k9 gold badges68 silver badges84 bronze badges

1 Comment

Timur Cetindag Over a year ago

Oh yeah, that was just a typo. I was just looking into the fnmatch function, and I got this far: 'for file in os.listdir('./'): if fnmatch.fnmatch(file,'kplr006933899*slc.fits'):' Now I want to be able to specify the beginning of the string, and maybe a list of possible ends for the string, like slc, llc, so then it would only loop through the files with slc or llc at the end of the filename.

Collectives™ on Stack Overflow

looping through specific files in python

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related