Is there a way in a huge python file , you just see the function def you are interested in ? I remember Eclipse has an option to do this in Java and it was pretty helpful.How about for Python in PyDev/Aptana Studio 3?
What you can do is use the regular outline (Alt+Shift+Q O) with a filter.
In case you can't really make a filter with just the functions you want, you can add comments to your code in the format: "#--- comment" and those comments should then appear in the outline and then do a filter that leaves only those comments available.
Note that sometimes the quick outline is already good enough (Ctrl+O), but it currently doesn't show those comments as the regular outline.
Another solution could be using bookmarks -- ctrl+F10, add bookmark -- there are tips for using the bookmarks properly at: How to navigate to a bookmark in eclipse 3.4.1?