As announced, in 0.18.0, the old PyYAML functions have been deprecated. (scan, parse, compose, load, emit, serialize, dump and their variants (_all, safe_, round_trip_, etc)). If you only read this after your program has stopped working: I am sorry to hear that, but that also means you, or the person developing your program, has not tested with warnings on (which is the recommendation in PEP 565,