Kevin Mehall has posted some python source code that is capable of accessing rtlsdr / GNU Radio samples directly.
“This script decodes the packets that Oregon Scientific remote thermometers (like the one pictured [above]) send to the display unit. It also serves as example code for accessing rtl-sdr / GNU Radio samples live from Python.
Each sensor transmits every 30 seconds on 433.9MHz. The packet is repeated twice. Modulation is On-off keying, and the 32 data bits are manchester encoded. “ — kevinmehall