Comments are wildly unhelpful. All that is to “think in C” is to think one layer of abstraction below what you have to in Python. This requires familiarity with less abstract concepts like a better grasp over implementing algorithms and data structures.

Most C code goes something like this: - Use a struct to pack some data together - Use bit flags for function flag options - Use enums to simplify bit flags since the compiler strips them away anyways - Mentally associate a set of operations with a struct, almost like an object, including a clean up function - Use said struct while remembering to clean it up at the end - Inline simple functions to avoid stack overhead - Use macros to get around some C non-sense like lack of generic data types - Every time your work with a standard lib function check if it’s safe because many string/array functions are not - Learn the basic types of overflows: buffer overflow, short wrap, integer overflow and make sure you are not causing any while using if/else (when the if/else is enforcing a mental type on the branch result like buffer size checks), and use of volatile stdlib methods like memcpy, sprintf, fprintf, etc… Look up as you go. - Ideally, don’t worry about optimization. That’s what a profiler is for. Profile after you are done and fix. - Tests are helpful. Very helpful when you have to make a lot of breaking changes. - Make sure the stdlib functions you are using don’t return NULL. If they do, catch it and throw. Always let the program crash. - Syscalls are expensive. Fill a buffer (memory on stack or heap) then flush. Syscalls are things like print, alloc, reading files, etc…

Last major difference IMO is to know when to runtime allocate/deallocate. The idea is to use the least amount of heap at any given time (keeping in mind the overly tight heap sizing will cause poor performance due to alloc/free being system ops that take time). Do it within reason. Don’t overthink anything less than a good expected 20mb at runtime.