How to make this code simply which uses argv, raw_input(), f.write() in Python

Question

What I Want:

write lines to file
simply code

It's ok if code don't need argv or some others

Here is my code:

from sys import argv

script, file_name = argv

target = open(file_name, 'w')

while True:
    line = raw_input()
    target.write(line)
    target.write("\n")
    if line.strip() == '':
        break

I found two question about it, but I'm a new learner with Python and I don't know how to combine the logic from the answers in these related questions.

write multiple lines in a file

Raw input across multiple lines

Hope I express clearly.Thanks.

Have you tried running the code? Does it work? I'm not sure what you're asking. — gr1zzly be4r, Mar 23 '16 at 16:12
Are you not getting output written in file? You are closing your file right? — Denis, Mar 23 '16 at 16:30
It can write lines to file, but I'm not sure about closing file right. — WillBC, Mar 23 '16 at 23:27

score 1 · Accepted Answer · edited May 23 '17 at 12:23

Your code will work but if you want to use writelines and the iter logic from both linked questions, you can use a for loop with iter(raw_input,"") which will loop until an empty string:

from sys import argv
script, file_name = argv

with open(file_name, 'w') as f:
    f.writelines(line+"\n" for line in iter(raw_input,""))

iter(raw_input,"") behaves link an infinite while loop, it will keep asking for input until the user just hits return, file.writelines takes an sequence of strings to write which we pass using a a generator expression.

If you were to use file.write, you just loop over the iter(raw_input, "") again and write in the loop:

with open(file_name, 'w') as f:
    for line in iter(raw_input, ""):
        f.write(line+"\n")

Denis · Answer 2 · 2016-03-23T16:38:08.290

if you want to only write then this code should be fine.This code takes the file name from user and then writes the data into file line by line. Execution stops when there is no data entered by user.

file_name = raw_input("Enter the file name")
target = open(file_name, 'w')
while True:
     line = raw_input("enter data")
     target.write(line)
     target.write("\n")
     if line.strip() == '':
         break
target.close()

How to make this code simply which uses argv, raw_input(), f.write() in Python

2 Answers2