GAE self.request.get IMG SRC to passing as a argument to python function

GAE self.request.get IMG SRC to passing as a argument to python function

Is there any way to get a img src so it can be pass aa an argument in GAE?
the images are not in database its in the html, say for eg: in index.html
I have some images & a user clicks on a image the page redirects to
images.html via a onClick js function with that selected image rendering
on images.html, Now to work with that image I need to pass it to my python
function/script?
If it would had been a text field it would be easy, we can get it via the
NAME value,right BUT how to get a image src value In short is there any
thing like self.request.get(IMG_SRC) #not from database but from the html
after post (post from index.html to image.html} ?
Or are there any module or python buildin function that is can be used for
getting the img src & passing it python function as an argument?