If hash tables were impossible to make in C, then it would be impossible to make them in Python, because it is a higher level language than C.

(Almost by definition, anything doable in a higher level language is doable in a lower level language, but not necessarily vice versa. In fact, many higher level languages are themselves written in lower level languages, e.g. Python is written in C.)

But Python has got dicts built into it, which are nothing but hash tables, and they are almost certainly written in C.

Google for some videos by Raymond Hettinger about Python dictionaries.

Or look at the source code of the Python interpreter.