How to convert a "long in a string" to a "long"?

[ondekoza at gmail.com]

Hello,

I need to convert the string "FFFFFFFF" to a long. To convert this
string I tried the following:
>>> 0xffffffff
-1
>>> 0xffffffffL
4294967295L

OK, this is what I want, so I tried

s = long("0xffffffffL")
ValueError: invalid literal for long(): 0xffffffffL

s = long("0xffffffff")
ValueError: invalid literal for long(): 0xffffffffL

What can I do? 

Thank you in advance.
Stefan