Fix Python 3 compatibility, remove some unused modules #1099

Job	Run time
build (ubuntu-latest, 3.7, gcc, g++, /usr/local/lib)	11m 54s
build (ubuntu-latest, 3.7, gcc, g++, /usr/local/lib)	12m 24s
build (ubuntu-latest, 3.8, gcc, g++, /usr/local/lib)	11m 52s
build (ubuntu-latest, 3.8, gcc, g++, /usr/local/lib)	14m 48s
build (ubuntu-latest, 3.9, gcc, g++, /usr/local/lib)	11m 54s
build (ubuntu-latest, 3.9, gcc, g++, /usr/local/lib)	12m 28s
build (ubuntu-latest, 3.10, gcc, g++, /usr/local/lib)	12m 2s
build (ubuntu-latest, 3.10, gcc, g++, /usr/local/lib)	12m 37s
build (ubuntu-latest, 3.11, gcc, g++, /usr/local/lib)	11m 56s
build (ubuntu-latest, 3.11, gcc, g++, /usr/local/lib)	11m 25s
build (ubuntu-latest, 3.12, gcc, g++, /usr/local/lib)	11m 35s
build (ubuntu-latest, 3.12, gcc, g++, /usr/local/lib)	12m 50s
build (macos-latest, 3.10, cc, c++, /opt/homebrew/lib/)	9m 47s
build (macos-latest, 3.10, cc, c++, /opt/homebrew/lib/)	9m 47s
build (ubuntu-latest, 3.10, clang, clang++, /usr/local/lib/)	11m 57s
build (ubuntu-latest, 3.10, clang, clang++, /usr/local/lib/)	12m 12s
	3h 11m 28s

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