Python. Phrase Representation, How To Change?

I don't know what's the encoding present in this phrases (and I'd like a answer to this too). Mainly, I'd like change my phrases to it. For example: Hello World! becomes Hello%20W

Solution 1:

>>> import urllib2
>>> urllib2.quote
<function quote at 0x104a10848>
>>> urllib2.quote("ü")
'%C3%BC'
>>> urllib2.quote('Olá mundo!')
'Ol%C3%A1%20mundo%21'