What do you use "true" threading for? Are you multiplying matrices? If so use Numpy. Are you downloading data and accessing database? If so, you threading, threading in Python works great for that. If you hit memory size issues, switch to gevent or eventlet for green threads.

I have been building large projects in Python for the last 10 yeas and never really thought "Hmm I wish I had more powerful lambda functions". You can always just have regular function and pass that around. Why do you need lambdas so much?