Python Replace \\ with \

Question

So I can't seem to figure this out... I have a string say, "a\\nb" and I want this to become "a\nb". I've tried all the following and none seem to work;

>>> a 'a\\nb' >>> a.replace("\\","\")   File "<stdin>", line 1     a.replace("\\","\")                       ^ SyntaxError: EOL while scanning string literal >>> a.replace("\\",r"\")   File "<stdin>", line 1     a.replace("\\",r"\")                        ^ SyntaxError: EOL while scanning string literal >>> a.replace("\\",r"\\") 'a\\\\nb' >>> a.replace("\\","\\") 'a\\nb' 

I really don't understand why the last one works, because this works fine:

>>> a.replace("\\","%") 'a%nb' 

Is there something I'm missing here?

EDIT I understand that \ is an escape character. What I'm trying to do here is turn all \\n \\t etc. into \n \t etc. and replace doesn't seem to be working the way I imagined it would.

>>> a = "a\\nb" >>> b = "a\nb" >>> print a a\nb >>> print b a b >>> a.replace("\\","\\") 'a\\nb' >>> a.replace("\\\\","\\") 'a\\nb' 

I want string a to look like string b. But replace isn't replacing slashes like I thought it would.

Answer 1

There's no need to use replace for this.

What you have is a encoded string (using the string_escape encoding) and you want to decode it:

>>> s = r"Escaped\nNewline" >>> print s Escaped\nNewline >>> s.decode('string_escape') 'Escaped\nNewline' >>> print s.decode('string_escape') Escaped Newline >>> "a\\nb".decode('string_escape') 'a\nb' 

In Python 3:

>>> import codecs >>> codecs.decode('\\n\\x21', 'unicode_escape') '\n!'