Django-替换视图中的字符后，将字符串正确传递到模板的问题

Question

I'm having a bizarre issue with passing a particular string from a view to a template.

The string originates from a form, and contains text that I want to simplify into a split-able string later. So, I substitute potential separator characters with a comma like so:

# views.py

mystring = myform.cleanedData['mystring']
mystring = str(mystring)  # convert from unicode
mystring = mystring.replace("\n", ",").replace("\r\n", ",").replace(" ", ",").replace(";", ",")

# Then I pass it to the template:
return render(request, 'html/mytemplate.html', {'mystring': mystring})

Now, take this form data for example:

%15
%16

If I print out mystring to a file just before rendering the template, it looks like this:

%15,%16

All good so far. The problem, though, comes from trying to render this string into the template. If I try to render the string like this:

{{ mystring }}

The result is this (leading spaces included):

    %15
,%16

It preserves the comma, but adds some other funky stuff, which I don't want because it makes some of my JS get pretty darn confused. I've tried to prevent escaping with the safe filter, but it doesn't seem to change anything in this case. Another thing to note is that if the original form data is already correctly formatted, ie "%15,%16", it works just fine and passes the string as intended.

Any ideas? I've done quite a bit of logging inside my views, but it seems to be fine up until I render it to the template.

Answer 1

Well, after looking at my own example code here, I realized what the issue was.

I needed to swap the order of replace("\\n", ",") with replace("\\r\\n", ",") , ensuring that the latter occurs first. The issue was caused by the \\n escapes being replaced, and then not being able to find any occurrences of \\r\\n , therefore leaving all of the \\r s in the text.