I'm unsure about your error. I just tried it in a pycharm project and it works fine here.
The double backslash is because the backslash is used as an escape character in python. So you need to escape it... with a backslash.
"The backslash (\) character is used to escape characters that otherwise have a special meaning, such as newline, backslash itself, or the quote character. String literals may optionally be prefixed with a letter `r' or `R'; such strings are called raw strings and use different rules for backslash escape sequences."
More info here:
https://docs.python.org/2.0/ref/strings.html