Unable to run python google app engine project

I am 开发者_运维技巧developing a tiny webapp on google app engine using python. I am using eclipse IDE for the development. When I tried to run the python webapp I am getting this error.

Status: 404 Not Found
Content-Type: text/html; charset=utf-8
Cache-Control: no-cache
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Content-Length: 0

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This is most probably an error on the Eclipse side. Try using the launcher to run the application.