CPython 3.3a4 appears to find treap/ before treap.py in the CWD.  If I rename treap to treap-dir, all seems well for the code in question:

dstromberg@zareason-limbo6000a /tmp/tt $ mv treap treap-dir

dstromberg@zareason-limbo6000a /tmp/tt $ /usr/local/cpython-3.3/bin/python -c 'import sys; print(sys.path); import treap; t = treap.treap()'
['', '/usr/local/cpython-3.3/lib/python33.zip', '/usr/local/cpython-3.3/lib/python3.3', '/usr/local/cpython-3.3/lib/python3.3/plat-linux', '/usr/local/cpython-3.3/lib/python3.3/lib-dynload', '/usr/local/cpython-3.3/lib/python3.3/site-packages']

dstromberg@zareason-limbo6000a /tmp/tt $ mv treap-dir/ treap

dstromberg@zareason-limbo6000a /tmp/tt $ /usr/local/cpython-3.3/bin/python -c 'import sys; print(sys.path); import treap; t = treap.treap()'
['', '/usr/local/cpython-3.3/lib/python33.zip', '/usr/local/cpython-3.3/lib/python3.3', '/usr/local/cpython-3.3/lib/python3.3/plat-linux', '/usr/local/cpython-3.3/lib/python3.3/lib-dynload', '/usr/local/cpython-3.3/lib/python3.3/site-packages']
Traceback (most recent call last):
  File "<string>", line 1, in <module>
AttributeError: 'module' object has no attribute 'treap'

dstromberg@zareason-limbo6000a /tmp/tt $ ls -l treap/__init__.py
ls: cannot access treap/__init__.py: No such file or directory

dstromberg@zareason-limbo6000a /tmp/tt $ /usr/local/cpython-3.3/bin/python
Python 3.3.0a4 (default, Jun  8 2012, 14:14:41)
[GCC 4.6.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
dstromberg@zareason-limbo6000a /tmp/tt $