Replace \n with

Question

I'm parsing text from a file with Python. I have to replace all newlines with  . I tried this code:

thatLine.replace('\n', '<br />')
print thatLine

But I still see the text with newline after it. Why?

Consider a CSS only solution: http://stackoverflow.com/a/7602751/74449 to reduce potential for XSS — Myster, Mar 19 '13 at 22:31

score 189 · Answer 1 · answered Dec 06 '10 at 17:28

189

thatLine = thatLine.replace('\n', ' ')

str.replace() returns a copy of the string, it doesn't modify the string you pass in.

answered Dec 06 '10 at 17:28

Falmarri

47,727
41
151
191

3

Welcome to StackOverflow. – Cecil Curry Sep 20 '17 at 06:36

score 71 · Accepted Answer · answered Dec 06 '10 at 17:32

71

Just for kicks, you could also do

mytext = "<br />".join(mytext.split("\n"))

to replace all newlines in a string with  .

answered Dec 06 '10 at 17:32

Tim Pietzcker

328,213
58
503
561

25

Thanks for accepting this, but please accept @Falmarri's answer instead. It's much more Pythonic. This here is more of a funny, backwards way of doing it. Not really recommended... – Tim Pietzcker Dec 06 '10 at 17:50
1

Don't know about @Falmarri's answer being "more Pythonic", but it's more efficient and probably faster. – martineau Dec 06 '10 at 20:28
4

@martineau: I meant this in the sense of "There should be one -- and preferably only one -- obvious way to do it.". And I'm pretty sure that mine isn't the one. – Tim Pietzcker Dec 06 '10 at 20:54
This was the only method that worked for my example and I tried a few! Thanks! – Eric Swiggum Feb 08 '23 at 17:30

score 23 · Answer 3 · answered Dec 21 '16 at 13:37

23

For some reason using python3 I had to escape the "\"-sign

somestring.replace('\\n', '')

Hope this helps someone else!

answered Dec 21 '16 at 13:37

Mikko P

468
6
7

2

Would give +2. 5 stars! – JJFord3 Jun 12 '19 at 18:01
If you use double quotes around the \n, you would not have to escape it. – Jordan Jul 23 '20 at 02:09
You might still need to escape it even if using double quotes – Bendemann Mar 21 '22 at 17:07

score 12 · Answer 4 · edited May 23 '17 at 12:10

12

To handle many newline delimiters, including character combinations like \r\n, use splitlines (see this related post) use the following:

'<br />'.join(thatLine.splitlines())

edited May 23 '17 at 12:10

Community

1
1

answered Apr 26 '17 at 18:05

teichert

3,963
1
31
37

score 8 · Answer 5 · edited Oct 17 '15 at 12:16

8

thatLine = thatLine.replace('\n', '<br />')

Strings in Python are immutable. You might need to recreate it with the assignment operator.

edited Oct 17 '15 at 12:16

Stefan van den Akker

6,661
7
48
63

answered Dec 06 '10 at 17:32

erickb

6,193
4
24
19

score 4 · Answer 6 · edited Oct 17 '15 at 12:15

4

You could also have problems if the string has <, > or & chars in it, etc. Pass it to cgi.escape() to deal with those.

http://docs.python.org/library/cgi.html?highlight=cgi#cgi.escape

edited Oct 17 '15 at 12:15

Stefan van den Akker

6,661
7
48
63

answered Dec 06 '10 at 17:59

greggo

3,009
2
23
22

score 3 · Answer 7 · answered Aug 05 '19 at 14:25

The Problem is When you denote '\n' in the replace() call , '\n' is treated as a String length=4 made out of ' \ n '
To get rid of this, use ascii notation. http://www.asciitable.com/

example:

newLine = chr(10)
thatLine=thatLine.replace(newLine , '<br />')

print(thatLine) #python3

print thatLine #python2 .

score 1 · Answer 8 · answered Mar 14 '20 at 11:16

I know this is an old thread but I tried the suggested answers and unfortunately simply replacing line breaks with   didn't do what I needed it to. It simply rendered them literally as text.

One solution would have been to disable autoescape like this: {% autoescape false %}{{ mystring }}{% endautoescape %} and this works fine but this is no good if you have user-provided content. So this was also not a solution for me.

So this is what I used:

In Python:

newvar = mystring.split('\n')

And then, passing newvar into my Jinja template:

{% for line in newvar %}
    <br />{{ line }}
{% endfor %}

score 0 · Answer 9 · edited May 16 '22 at 12:21

0

If in case you are trying to replace the /n of a string to , i am speculating that you want to parse line break in HTML view.

word-break: break-all,
white-space: pre-wrap;

Adding these to styles to parent div/container of the text will solve your problem without any string manipulations.

edited May 16 '22 at 12:21

Martijn Pieters

1,048,767
296
4,058
3,343

answered May 16 '22 at 10:28

JJY9

100
9

score 0 · Answer 10 · answered Jun 29 '22 at 17:54

If you are wanting to do this using replace, and the
is not working for you (as was the case for me), you can use the following:

text_to_split = r'Hello\n\n I am a test.'
split_text = text_to_split.replace('\\n', '\n')

You first escape the \ in the sample text, and then by not escaping in the replacement text, it will generate a new line.

Replace \n with

10 Answers10

Linked