py bindings -- more minor fixes
py bindings -- more minor fixes


Former-commit-id: 95ac99cac11360c22041f3b2e1775fc64588e860
Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide