string - using backslash in python (not to escape)

Question

import os
path= os.getcwd()
final= path +'\xulrunner.exe ' + path + '\application.ini'
print final

I want the out put:

c:\python25\xulrunner.exe c:\python25\application.ini

I don't want backslash to work as string, i mean don't want it to escape or do anything special. But i get an error

Invalid \x escape

How can i use a '\' as a '\' and not an escape?

Answer 1

To answer your question directly, put r in front of the string.

final= path + r'\xulrunner.exe ' + path + r'\application.ini'

But a better solution would be os.path.join:

final = os.path.join(path, 'xulrunner.exe') + ' ' + \
         os.path.join(path, 'application.ini')

(the backslash there is escaping a newline, but you could put the whole thing on one line if you want)

I will mention that you can use forward slashes in file paths, and Python will automatically convert them to the correct separator (backslash on Windows) as necessary. So

final = path + '/xulrunner.exe ' + path + '/application.ini'

should work. But it's still preferable to use os.path.join because that makes it clear what you're trying to do.

Answer 2

You can escape the slash. Use \\ and you get just one slash.

Answer 3

You can escape the backslash with another backslash (\\), but it won’t look nicer. To solve that, put an r in front of The string to signal a raw string. A raw string will ignore literally everything , which is a bad thing if you also want colored text, and really bad if your string contains some quotes like this:

a_and_b = r”Alice’s friend is Bob. He always says, \“howdy\” ”

In this case, python will throw a SyntaxError...

---

If you haven’t figured out how to solve it, here it is:

a_and_b = r”””Alice’s friend is Bob. He always says, \“howdy\” ””” In here, we use a multiline string. And if the string has 3 quotes in a row, then that’s easy. Put a space between them and it’s solved:

three_quotes = ’’’ Here are 3 single quotes: ‘ ‘ ‘ ’’’

Answer 4

Another simple (and arguably more readable) approach is using string raw format and replacements like so:

import os
path = os.getcwd()
final = r"{0}\xulrunner.exe {0}\application.ini".format(path)
print(final)

or using the os path method (and a microfunction for readability):

import os

def add_cwd(path):
    return os.path.join( os.getcwd(), path )

xulrunner = add_cwd("xulrunner.exe")
inifile = add_cwd("application.ini")
# in production you would use xulrunner+" "+inifile
# but the purpose of this example is to show a version where you could use any character
# including backslash
final = r"{} {}".format( xulrunner, inifile )
print(final)