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: 
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!'

```
You are missing, that \ is the escape character.

Look here: <http://docs.python.org/reference/lexical_analysis.html>
at 2.4.1 "Escape Sequence"

Most importantly \n is a newline character.
And \\ is an escaped escape character :D

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

```