Switch generated Cython code fragments to "language_level=3str".
Switch generated Cython code fragments to "language_level=3str".

cython/cython,cython/cython,cython/cython,da-woods/cython,da-woods/cython,cython/cython,da-woods/cython,scoder/cython,da-woods/cython,scoder/cython,scoder/cython,scoder/cython