Appending a string in front of every item in the file using Python

Question

The following is what I am trying to achieve:

my_list = ['foo', 'fob', 'faz', 'funk']

string = 'bar'

my_new_list = [ string + x for x in my_list]

print my_new_list

The problem is all my words are in a text file. Example:

foo

fob

faz

funk

How to read the text file and write a loop to append the word 'bar' in front of each word and generate a new file?

Answer 1

Like that?

with open("myfile.txt") as f, open("output.txt", "w") as out:
    for line in f:
        out.write("bar" + line)

Answer 2

You can get a list of lines in a file using readlines() and you can write lines to a file using writelines() :

with open('/path/to/infile') as infile:
    lines = infile.readlines()

string = 'bar'
my_new_list = [string + x for x in lines]

with open('/path/to/outfile', 'w') as outfile:
    outfile.writelines(my_new_list)

Answer 3

file_object = open('example.txt','r')
output = open('data','w+')
string = 'bar'
for line in file_object:
    output.write(string+line)
file_object.close()
output.close()

this is may help you.