combine multiple text files into one text file using python [duplicate]

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?

Betts

this thread is a ducplicate of #13613836 – Sext

cat *.txt > all.txt – Ferdelance

Answer 1

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())

Disruption

thank you. i accepted your answer because your code is powerful. since i am new, can you explain infile.read() procedure.@Disruption – Betts

The .read() method of a file handle reads the contents of a file and produces a string of it's contents. – Disruption

nice one apiguy!! – Meghan

Is there a way to do it column wise? – Valais

The most effective way I came across. Thank you :) – Moria

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 :) – Geest

Answer 2

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)

Finnish

That's probably the most efficient method and works perfectly in Python 2.7 – Kerrin

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. – Bummer

Answer 3

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.

Malinin

Answer 4

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

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

Noneffective

This is not portable approach. – Brachium

This is the answer that worked for me! Thanks. – Vig

Answer 5

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)

Brotherson

add some explanation to your answer. – Decolorant

line by line reading/writing a file is not the same as reading / writing the bytes of a file. just FYI. – Mcgrew