python replace single backslash with double backslash

In python \ (backslash) is used as an escape character. What this means that in places where you wish to insert a special character (such as newline), you would use the backslash and another character (\n for newline)

With your example string you would notice that when you put "C:\Users\Josh\Desktop\20130216" in the repl you will get "C:\\Users\\Josh\\Desktop\x8130216". This is because \2 has a special meaning in a python string. If you wish to specify \ then you need to put two \\ in your string.

"C:\\Users\\Josh\\Desktop\\28130216"

The other option is to notify python that your entire string must NOT use \ as an escape character by pre-pending the string with r

r"C:\Users\Josh\Desktop\20130216"

This is a "raw" string, and very useful in situations where you need to use lots of backslashes such as with regular expression strings.

In case you still wish to replace that single \ with \\ you would then use:

directory = string.replace(r"C:\Users\Josh\Desktop\20130216", "\\", "\\\\")

Notice that I am not using r' in the last two strings above. This is because, when you use the r' form of strings you cannot end that string with a single \

Why can't Python's raw string literals end with a single backslash?

https://pythonconquerstheuniverse.wordpress.com/2008/06/04/gotcha-%E2%80%94-backslashes-are-escape-characters/

No need to use str.replace or string.replace here, just convert that string to a raw string:

>>> strs = r"C:\Users\Josh\Desktop\20130216"
           ^
           |
       notice the 'r'

Below is the repr version of the above string, that's why you're seeing \\ here. But, in fact the actual string contains just '\' not \\.

>>> strs
'C:\\Users\\Josh\\Desktop\\20130216'

>>> s = r"f\o"
>>> s            #repr representation
'f\\o'
>>> len(s)   #length is 3, as there's only one `'\'`
3

But when you're going to print this string you'll not get '\\' in the output.

>>> print strs
C:\Users\Josh\Desktop\20130216

If you want the string to show '\\' during print then use str.replace:

>>> new_strs = strs.replace('\\','\\\\')
>>> print new_strs
C:\\Users\\Josh\\Desktop\\20130216

repr version will now show \\\\:

>>> new_strs
'C:\\\\Users\\\\Josh\\\\Desktop\\\\20130216'

Use escape characters: "full\\path\\here", "\\" and "\\\\"

Let me make it simple and clear. Lets use the re module in python to escape the special characters.

Python script :

import re
s = "C:\Users\Josh\Desktop"
print s
print re.escape(s)

Output :

C:\Users\Josh\Desktop
C:\\Users\\Josh\\Desktop

Explanation :

Now observe that re.escape function on escaping the special chars in the given string we able to add an other backslash before each backslash, and finally the output results in a double backslash, the desired output.

Hope this helps you.