I don't know much python but from what I can tell from the documentation the code:
str = "AAAA"
str += pack("<I", 0)
would append the result of the pack function to str, which would be the integer value of 0 in little-endian style. My question is what the C equivalent of this would be. Would it just be:
char str[20] = "AAAA";
strcat(str, "\x00");
?...