Correct Way to Write Line to File

Correct way to write line to file?

This should be as simple as:

with open('somefile.txt', 'a') as the_file:
    the_file.write('Hello\n')

From The Documentation:

Do not use os.linesep as a line terminator when writing files opened in text mode (the default); use a single '\n' instead, on all platforms.

Some useful reading:

• The with statement
• open()
  
  • 'a' is for append, or use
  • 'w' to write with truncation
• os (particularly os.linesep)

Python write line by line to a text file

Well, the problem you have is wrong line ending/encoding for notepad. Notepad uses Windows' line endings - \r\n and you use \n.

Write text to file line by line

This is how to print to a txt file:

file = open("Exported.txt", "w")
file.write("Text to write to file")
file.close() #This close() is important

Another way to do so would to be:

with open('Exported.txt', 'w') as file:
   file.write("Text to write to file")

This is a program I made to write a txt file:

import os.path

def start():

    print("What do you want to do?")
    print("    Type a to write a file")
    print("    Type b to read a file")
    choice = input("            -")
    if choice == "a":
        create()
    elif choice == "b":
        read()
    else:
        print("Incorrect spelling of a or b\n\n")
        start()


def create():

    print()
    filename = input("What do you want the file to be called?\n")
    if os.path.isfile(filename):
        print("This file already exists")
        print("Are you sure you would like to overwrite?")
        overwrite = input("y or n")
        if overwrite == "y":
            print("File has been overwritten")
            write(filename)
        else:
            print("I will restart the program for you")
    elif not os.path.isfile(filename):
        print("The file has not yet been created")
        write(filename)
    else:
        print("Error")





def write(filename):
    print()
    print("What would you like the word to end writing to be?")
    keyword = input()
    print("What would you like in your file?")
    text = ""
    filename = open(filename, 'w')
    while text != keyword:
        filename.write(text)
        filename.write("\n")
        text = input()


def read():
    print()
    print("You are now in the reading area")
    filename = input("Please enter your file name:     -")
    if os.path.isfile(filename):
        filename = open(filename, 'r')
        print(filename.read())
    elif not os.path.isfile(filename):
        print("The file does not exist\n\n")
        start()
    else:
        print("Error")


start()

Write lines of text to a file in R

fileConn<-file("output.txt")
writeLines(c("Hello","World"), fileConn)
close(fileConn)

Python - Write to file is written as one long line ['text\n...text\n...'] - need to have it as the original

There are several problems here:

1. Opening a text file in binary mode
2. Reading the entire file into memory
3. Trying to write a list to the new file instead of a number of individual lines.

Use itertools.islice to create a new iterator that skips the first 100 lines, then yields the next 400 lines, which you can iterate over using an ordinary for loop to write to the output file.

from itertools import islice


with open('my_file.log', 'r') as f:
    with open('LocalLogFile.txt', 'a') as x:
        for line in islice(f, 100, 150):
            print(line, file=x, end='')

Some might prefer a single with statement:

with open('my_file.log', 'r') as f, open('LocalLogFile.txt', 'a') as x:
    for line in islice(f, 100, 150):
        print(line, file=x, end='')

or

with open('my_file.log', 'r') as f, \
     open('LocalLogFile.txt', 'a') as x:
    for line in islice(f, 100, 150):
        print(line, file=x, end='')

Python 3.10 will make it possible to parenthesize multiple context managers, allowing you to use multiple lines without explicit line continuation:

with (
    open('my_file.log', 'r') as f,
    open('LocalLogFile.txt', 'a') as x
):
    for line in islice(f, 100, 150):
        print(line, file=x, end='')

Write a line into a .txt file with Node.js

Inserting data into the middle of a text file is not a simple task. If possible, you should append it to the end of your file.

The easiest way to append data some text file is to use build-in fs.appendFile(filename, data[, options], callback) function from fs module:

var fs = require('fs')
fs.appendFile('log.txt', 'new data', function (err) {
  if (err) {
    // append failed
  } else {
    // done
  }
})

But if you want to write data to log file several times, then it'll be best to use fs.createWriteStream(path[, options]) function instead:

var fs = require('fs')
var logger = fs.createWriteStream('log.txt', {
  flags: 'a' // 'a' means appending (old data will be preserved)
})

logger.write('some data') // append string to your file
logger.write('more data') // again
logger.write('and more') // again

Node will keep appending new data to your file every time you'll call .write, until your application will be closed, or until you'll manually close the stream calling .end:

logger.end() // close string

Note that logger.write in the above example does not write to a new line. To write data to a new line:

var writeLine = (line) => logger.write(`\n${line}`);
writeLine('Data written to a new line');

Writing string to a file on a new line every time

Use "\n":

file.write("My String\n")

See the Python manual for reference.

for each line in file write line to an individual file in python

Read the lines from the file in a loop, maintaining the line number; open a file with the name derived from the line number, and write the line into the file:

f1 = open('main_file', 'r')
for i,text in enumerate(f1):
    open(str(i + 1) + '.txt', 'w').write(text)

Is there a simple way to write multiple lines to a text file?

Try this. I can't run your script because no variables are defined

output = receipt()
file = open("sample.txt","w")
file.write(output)
file.close()

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