opening files in directory

[Rebecca_2]

Hi,
I have a quick, and what seems like very stupid question.

I have a list of files in a directory with various extensions. I want to open only the ones with the extension '.txt'.

I have got as far as finding them (and can print their filenames to a new file) but don't seem to be able to open the files themselves to extract their data. Here is the code I have so far:

import os

writer=open('psub', 'w')
writer.close()

for files in os.listdir('.'):
    if files.endswith('.txt'):
        writer=open('psub', 'a')
        print(files, file=writer)
        writer.close()

How then, do I go on to open and read the '.txt' files?

Any pointers would be very appreciated...

Cheers

[rrashkin]

First of all, you probably don't need to close and open "writer" at every step. It's just creating a lot of overhead. Open it once as you do before the loop and close it once afterward.
As for the reading files, instead of writer=open('psub', 'a'), which I recommend you remove, put reader=open(files) (open for reading is the default). Then change the close to reader.close().

[vegaseat]

Another approach ...

# find selected files in the working folder using module glob
# glob takes care of upper/lower case
# for instance it finds .txt .Txt .TXT etc.
# glob works with Windows and Unix

import os
import glob

# pick a directory/folder
folder = "C:/temp"
os.chdir(folder)

print("list of all .txt files in folder {} ...".format(folder))
for fname in glob.glob('*.txt'):
    print(fname)

[vegaseat]

This will create a file of all .txt files in the selected directory ...

import os
import glob

# pick a directory/folder
folder = "C:/temp"
os.chdir(folder)

file_list = glob.glob('*.txt')

with open("my_filelist.txt", "w") as fout:
    fout.write("".join(fname + '\n' for fname in file_list))

[vegaseat]

This will read the content of all .txt files in a given folder ...

import os
import glob

# pick a directory/folder
folder = "C:/temp"
os.chdir(folder)

print("read content of all .txt files in folder {} ...".format(folder))
for fname in glob.glob('*.txt'):
    print(fname)
    print('-'*70)  # line of 70 dashes, cosmetic
    with open(fname) as fin:
        print(fin.read())
        print('-'*70)