I want to use the json1 extension for SQLite within Python. According to the official documentation, it should be a loadable extension. I got the json1.c file from the source an
For anyone who's still trying to figure out how to build the json1 extension from source code, here it is:
After you download the latest release source code from SQLite Source Repository, unzip it, cd into its folder and run ./configure. 
Then add the following to the generated Makefile:
json1.dylib: json1.lo  
    $(LTCOMPILE) -c $(TOP)/ext/misc/json1.c  
    $(TCC) -shared -o json1.dylib json1.o  
make is finicky, so be sure $(LTCOMPILE) and $(TCC) are preceded by TAB, not spaces!
Then run make json1.dylib
Reference: https://burrows.svbtle.com/build-sqlite-json1-extension-as-shared-library-on-os-x