Problems replacing \ with \\

[Gabriel Genellina]

(top posting corrected)

En Mon, 21 Apr 2008 21:12:44 -0300, ockman at gmail.com <ockman at gmail.com>  
escribió:

>> > def escape(string):
>> >     """
>> >     Escape both single quotes and blackslashes
>> >     >>> x = r"fun\fun"
>> >     >>> escape(x)
>> >     'fun\\\\fun'
>> >     """
>> >     string = string.replace('\\', '\\\\')
>> >     return string
>>
>> > Failed example:
>> >     escape(x)
>> > Expected:
>> >     'fun\\fun'
>> > Got:
>> >     'fun\x0cun'
>>
>> Your doctest is in a triple-quoted string which contains the line:
>>
>> >>> x = r"fun\fun"
>> which is the same as:
>>
>> >>> x = r"fun\x0cun"
>>
>> If you wrap a raw string in just quotes that is isn't a raw string any
>> longer!

> Thank you for the response.  I'm not sure I understand the last
> sentence, although I think I get the idea.  How do I create a proper
> doctest?

r"This is a raw string"

"""
     r"This is NOT a raw string"
"""

r"""
     r"This is a raw string too"
"""

What matters are the OUTER quotes.

Now, why do you want to escape the text yourself? Assuming you have a  
DBAPI compatible module, use bound parameters when you execute the query:

   cursor.execute("insert ... values (?,?,?)", (name, address, year))

Those ? are placeholders for the actual values; no explicit quoting on the  
values is required (the module itself, or the database, takes care of it).  
Not all databases support the ? style, there are other ways. See  
http://www.python.org/dev/peps/pep-0249/ for the DB API specification.

-- 
Gabriel Genellina