How to intercept special (alt / ctrl) key press?

Question

How can I catch key combinations like ALT+K or CTRL+ALT+H in python curses?

Answer 1

A terminal converts the control key in combination with a letter key to a normal ASCII code. This can be read from the getch() function like any other key press.

CTRL-A: getch() returns 1
CTRL-B: getch() returns 2
...
CTRL-Z: getch() returns 26

Also, the keypad() function must be called to enable other special function keys (e.g. left arrow, F1, home, etc).

I don't believe there is a portable way to receive meta-keys (e.g. ALT-H) through a terminal. Some send an escape (0x1B) followed by the modified key while others set the high-bit and only send one byte.