Decompyle is a python disassembler and decompiler which converts Python byte-code (.pyc or .pyo) back into equivalent Python source. Verification of the produced code (re-compiled) is avaliable as well.
jbytecode is a Java bytecode disassembler/assembler written in Python. Dissasembly code is aligned with Java bytecodes in the class file so modification and re-assembly is always possible, even when class is obfuscated.