I want to append a newline to my string every time I call file.write(). What's the easiest way to do this in Python? alex 5,8699 gold badges48 silver badges99 bronze badges asked May 27, 2010 at 3:56 Use "\n": file.write("My String\n")
See the Python manual for reference. James MV
8,43116 gold badges63 silver badges92 bronze badges answered May 27, 2010 at 3:59 halfdanhalfdan 32.7k8 gold badges76 silver badges86 bronze badges 4 You can do this in two ways: f.write("text to write\n")
or, depending on your Python version (2 or 3): print >>f, "text to write" # Python 2.x
print("text to write", file=f) # Python 3.x
answered May 27, 2010 at 3:58 Greg HewgillGreg Hewgill 907k177 gold badges1131 silver
badges1267 bronze badges 3 You can use: file.write(your_string + '\n')
Tot Zam 7,9699 gold badges49 silver badges72 bronze badges answered
May 27, 2010 at 4:00 Krishna
KKrishna K 1,8151 gold badge14 silver badges11 bronze badges 2 If you use it extensively (a lot of written lines), you can subclass 'file': class cfile(file):
#subclass file to have a more convienient use of writeline
def __init__(self, name, mode = 'r'):
self = file.__init__(self, name, mode)
def wl(self, string):
self.writelines(string + '\n')
Now it offers an additional function wl that does what you want: with cfile('filename.txt', 'w') as fid:
fid.wl('appends newline charachter')
fid.wl('is written on a new line')
Maybe I am missing something like different newline characters (\n, \r, ...) or that the last line is also terminated with a newline, but it works for me. answered Jun 12, 2014 at 12:02
mathausemathause 1,4571 gold
badge14 silver badges24 bronze badges 2 you could do: file.write(your_string + '\n')
as suggested by another answer, but why using
string concatenation (slow, error-prone) when you can call file.write twice: file.write(your_string)
file.write("\n")
note that writes are buffered so it amounts to the same thing. answered Mar 3, 2019 at 14:42 Another solution that writes from a list using fstring lines = ['hello','world']
with open('filename.txt', "w") as fhandle:
for line in lines:
fhandle.write(f'{line}\n')
And as a function def write_list(fname, lines):
with open(fname, "w") as fhandle:
for line in lines:
fhandle.write(f'{line}\n')
write_list('filename.txt', ['hello','world'])
answered Jan 12, 2020 at 21:08
citynormancitynorman 4,4002 gold
badges34 silver badges37 bronze badges 0 file_path = "/path/to/yourfile.txt"
with open(file_path, 'a') as file:
file.write("This will be added to the next line\n")
or log_file = open('log.txt', 'a')
log_file.write("This will be added to the next line\n")
answered
Jan 24, 2018 at 14:49 Panos Kal.Panos Kal. 12.3k8 gold badges64 silver badges79 bronze badges 1 Unless
write to binary files, use print. Below example good for formatting csv files: def write_row(file_, *columns):
print(*columns, sep='\t', end='\n', file=file_)
Usage: PHI = 45
with open('file.csv', 'a+') as f:
write_row(f, 'header', 'phi:', PHI, 'serie no. 2')
write_row(f) # additional empty line
write_row(f, data[0], data[1])
You can also use partial as a more pythonic way of creating this kind of wrappers. In the example below, row is print with predefined kwargs. from functools import partial
with open('file.csv', 'a+') as f:
row = partial(print, sep='\t', end='\n', file=f)
row('header', 'phi:', PHI, 'serie no. 2', end='\n\n')
row(data[0], data[1])
Notes: - print documentation
'{}, {}'.format(1, 'the_second') -
https://pyformat.info/, PEP-3101- '\t' - tab character
*columns in function definition - dispatches any number of arguments to list - see question on *args & **kwargs
answered
Apr 16, 2019 at 20:58 MescoMesco 1,05712 silver badges17 bronze badges Just a note, file isn't supported in Python 3 and was removed. You can do the same
with the open built-in function. f = open('test.txt', 'w')
f.write('test\n')
answered Jan 21, 2018 at 9:00 user1767754user1767754 21.8k14 gold badges133 silver badges153 bronze badges I really didn't want to type \n every single time and @matthause's answer didn't seem to work for me, so I created my own class class File():
def __init__(self, name, mode='w'):
self.f = open(name, mode, buffering=1)
def write(self, string, newline=True):
if newline:
self.f.write(string + '\n')
else:
self.f.write(string)
And here it is implemented f = File('console.log')
f.write('This is on the first line')
f.write('This is on the second line', newline=False)
f.write('This is still on the second line')
f.write('This is on the third line')
This should show in the log file as This is on the first line
This is on the second lineThis is still on the second line
This is on the third line
answered
Dec 2, 2020 at 21:20 joshjosh
3541 silver badge16 bronze badges Using append (a) with open() on a print() statement looks easier for me: save_url = ".\test.txt"
your_text = "This will be on line 1"
print(your_text, file=open(save_url, "a+"))
another_text = "This will be on line 2"
print(another_text, file=open(save_url, "a+"))
another_text = "This will be on line 3"
print(another_text, file=open(save_url, "a+"))
answered May 12, 2021 at 11:31 Nwoye CIDNwoye CID 6687 silver badges8 bronze badges This is the solution that I came up with trying to solve this problem for myself in order to systematically produce \n's as separators. It writes using a list of strings where each string is one line of the file, however it seems that it may work for you as well. (Python 3.+) #Takes a list of strings and prints it to a file.
def writeFile(file, strList):
line = 0
lines = []
while line < len(strList):
lines.append(cheekyNew(line) + strList[line])
line += 1
file = open(file, "w")
file.writelines(lines)
file.close()
#Returns "\n" if the int entered isn't zero, otherwise "".
def cheekyNew(line):
if line != 0:
return "\n"
return ""
answered Mar 11, 2018 at 22:16
democidistdemocidist 951 silver badge6
bronze badges 1 Ok, here is a safe way of doing it. with open('example.txt', 'w') as f:
for i in range(10):
f.write(str(i+1))
f.write('\n')
This writes 1 to 10 each number on a new line. answered
Jan 18, 2021 at 17:25 You can decorate method write in specific place where you need this behavior: #Changed behavior is localized to single place.
with open('test1.txt', 'w') as file:
def decorate_with_new_line(method):
def decorated(text):
method(f'{text}\n')
return decorated
file.write = decorate_with_new_line(file.write)
file.write('This will be on line 1')
file.write('This will be on line 2')
file.write('This will be on line 3')
#Standard behavior is not affected. No class was modified.
with open('test2.txt', 'w') as file:
file.write('This will be on line 1')
file.write('This will be on line 1')
file.write('This will be on line 1')
answered Mar 23, 2021 at 14:54 Usually you would use \n but for
whatever reason in Visual Studio Code 2019 Individual it won't work. But you can use this: # Workaround to \n not working
print("lorem ipsum", file=f) **Python 3.0 onwards only!**
print >>f, "Text" **Python 2.0 and under**
answered Aug 11, 2021 at 3:10 If write is a callback, you may need a custom writeln. def writeln(self, string):
self.f.write(string + '\n')
Itself inside a custom opener. See answers and feedback for this question : subclassing file objects (to extend open and close operations) in python 3 (Context
Manager) I faced this when using ftplib to "retrieve lines" from a file that was "record based" (FB80): with open('somefile.rpt', 'w') as fp:
ftp.retrlines('RETR USER.REPORT', fp.write)
and ended up with one long record with no newlines, this is likely a problem with ftplib, but obscure. So this became: with OpenX('somefile.rpt') as fp:
ftp.retrlines('RETR USER.REPORT', fp.writeln)
It does the job. This is a use case a few people will be looking for. Complete declaration (only the last two lines are mine): class OpenX:
def __init__(self, filename):
self.f = open(filename, 'w')
def __enter__(self):
return self.f
def __exit__(self, exc_type, exc_value, traceback):
self.f.close()
def writeln(self, string):
self.f.write(string + '\n')
answered Nov 8, 2021 at 0:10
mckenzmmckenzm 1,2091 gold badge10 silver
badges17 bronze badges in order to suspport multiple operating systems use: file.write(f'some strings and/or {variable}. {os.linesep}') answered Mar 15 at 12:48
Assaf-geAssaf-ge 4164 silver badges6 bronze
badges You could use C-style string formatting: file.write("%s\n" % "myString")
More about String
Formatting. answered Jun 1 at 23:48 | 
