help me use proxy with twill

I read help here http://twill.idyll.org/browsing.html, then i open python and write

export http_proxy="http://www.so开发者_StackOverflow社区meproxy.com:3128"

but i just receive an error. How can i use proxy with twill to browser web ?

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the export command is something you need to type on your shell (assuming unix/linux). It's not a python statement!