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])

Answer 1

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