writing lines from multiple text files into one text file

[Laura P]

I am new to python, and coding in general. Looking at the code below, why is my master file writing the lines from each text file twice?

import os
import glob
FileName = "master.txt"
fout = open(FileName, "w")
for filename in glob.glob("*txt"):
    fin = open(filename, "r")
    lines = fin.readlines()
    fin.close()
    for lidx in lines:
        fout.write( "%s" % lidx )
fout.close()

The combined file I am getting looks like this:
text from file1
text from file2
text from file3
text from file1
text from file2
text from file3

Any help is appreciated.

[PythonInspired]

This code works exactly as you want it to when I test it.

By chance, do you have any links to these files in the same directory? I know that sounds odd, but when I create links to any of the files I tested this code with, the contents of the linked file were doubled in the output. (the glob section of the python documentation explains this).

I hope this is of some use, because otherwise your code works perfectly for me.

Anything more than this and I am absolutely useless. I am a beginner and decided that the best way to improve is to keep looking at code and trying to figure things out as I go.

[bvdet]

I don't see anything wrong with your code either. I have a suggestion for improving your code. Instead of

    for lidx in lines:
        fout.write( "%s" % lidx )

I prefer

    fout.write("".join(lines))