Some examples:

   > def fnord(): pass
   > fnord<f2> # doesn't work
   > class Foo(object): pass
   > Foo<f2> # doesn't work

Both of these work fine in iPython. Putting these two definitions in a file and importing them yields the same result - source does not show.

These are reduced examples, in my testing I noticed that I could show the source of a whole class in my project, but I wasn't able to show most of the methods on it. Some examples: properties, decorated methods, inherited methods.

Not sure whats the reason for this, but iPython did work for those most of the time, so it may be a good idea to fork their method source lookup code and use it instead of what is in bpython right now.