combine multiple text files into one text file using python

Question

suppose we have many text files as follows:

file1:

abc
def
ghi

file2:

ABC
DEF
GHI

file3:

adfafa

file4:

ewrtwe
rewrt
wer
wrwe

How can we make one text file like below:

result:

abc
def
ghi
ABC
DEF
GHI
adfafa
ewrtwe
rewrt
wer
wrwe

Related code may be:

import csv
import glob
files = glob.glob('*.txt')
for file in files:
with open('result.txt', 'w') as result:
result.write(str(file)+'\n')

After this? Any help?

this thread is a ducplicate of http://stackoverflow.com/questions/13613336/python-concatenate-text-files — sancelot, Jul 01 '14 at 12:41

score 81 · Accepted Answer · answered Jul 19 '13 at 14:59

81

You can read the content of each file directly into the write method of the output file handle like this:

import glob

read_files = glob.glob("*.txt")

with open("result.txt", "wb") as outfile:
    for f in read_files:
        with open(f, "rb") as infile:
            outfile.write(infile.read())

answered Jul 19 '13 at 14:59

apiguy

5,184
1
22
24

thank you. i accepted your answer because your code is powerful. since i am new, can you explain infile.read() procedure.@apiguy – Jul 19 '13 at 15:34
The `.read()` method of a file handle reads the contents of a file and produces a string of it's contents. – apiguy Jul 22 '13 at 14:42
nice one apiguy!! – ASH Sep 18 '18 at 20:47
Is there a way to do it column wise? – Sufyan Mar 08 '21 at 13:41
The most effective way I came across. Thank you :) – sediq khan May 12 '22 at 14:47
`import glob; outfile = open("out.txt", "wb"); [outfile.write(open(f, "rb").read()) for f in glob.glob("*.txt")]` just for the fun of having a one-liner :) – Basj May 17 '22 at 07:32

score 17 · Answer 2 · answered Jul 19 '13 at 15:01

17

The fileinput module is designed perfectly for this use case.

import fileinput
import glob

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

with open('result.txt', 'w') as file:
    input_lines = fileinput.input(file_list)
    file.writelines(input_lines)

answered Jul 19 '13 at 15:01

llb

1,581
9
14

That's probably the most efficient method and works perfectly in Python 2.7 – user113478 Feb 09 '17 at 12:10
The risk with this code is that if you already have a `result.txt` file (say, you're running it a second time), the process never ends and builds an ever-increasing sized file. – monkee Dec 11 '19 at 19:56

score 8 · Answer 3 · answered Jul 19 '13 at 14:58

8

You could try something like this:

import glob
files = glob.glob( '*.txt' )

with open( 'result.txt', 'w' ) as result:
    for file_ in files:
        for line in open( file_, 'r' ):
            result.write( line )

Should be straight forward to read.

answered Jul 19 '13 at 14:58

Robert Caspary

1,500
9
7

score 2 · Answer 4 · edited Feb 22 '17 at 14:32

2

It is also possible to combine files by incorporating OS commands. Example:

import os
import subprocess
subprocess.call("cat *.csv > /path/outputs.csv")

edited Feb 22 '17 at 14:32

Knak

488
3
14

answered May 17 '16 at 10:46

Sadheesh

797
6
6

4

This is not portable approach. – KeshV Jul 01 '16 at 18:31
This is the answer that worked for me! Thanks. – Denis Apr 04 '19 at 13:20

score 0 · Answer 5 · edited Jun 04 '15 at 17:17

0

filenames = ['resultsone.txt', 'resultstwo.txt']
with open('resultsthree', 'w') as outfile:
    for fname in filenames:
        with open(fname) as infile:
            for line in infile:
                outfile.write(line)

edited Jun 04 '15 at 17:17

Celeo

5,345
8
38
40

answered Jun 04 '15 at 16:20

proma

11

add some explanation to your answer. – HaveNoDisplayName Jun 04 '15 at 16:38
line by line reading/writing a file is not the same as reading / writing the bytes of a file. just FYI. – Mike McMahon May 16 '16 at 19:12

combine multiple text files into one text file using python

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