Newbe Dev Stack

Answer : For (at least) Python 3.7 According to the docs: bytes objects are immutable sequences of single bytes bytearray objects are a mutable counterpart to bytes objects. And that's pretty much it as far as bytes vs bytearray . In fact, they're fairly interchangeable and designed to flexible enough to be mixed in operations without throwing errors. In fact, there is a whole section in the official documentation dedicated to showing the similarities between the bytes and bytearray apis. Some clues as to why from the docs: Since many major binary protocols are based on the ASCII text encoding, bytes objects offer several methods that are only valid when working with ASCII compatible data and are closely related to string objects in a variety of other ways. In Python 2.6 bytes is merely an alias for str . This "pseudo type" was introduced to [partially] prepare programs [and programmers!] to be converted/compatible with Python 3.0 where there is a ...

Answer : Easiest is to make a union: #include <stdio.h> int main(void) { int ii; union { float a; unsigned char bytes[4]; } thing; thing.a = 1.234; for (ii=0; ii<4; ii++) printf ("byte %d is %02x\n", ii, thing.bytes[ii]); return 0; } Output: byte 0 is b6 byte 1 is f3 byte 2 is 9d byte 3 is 3f Note - there is no guarantee about the byte order… it depends on your machine architecture. To get your function to work, do this: void float2Bytes(byte bytes_temp[4],float float_variable){ union { float a; unsigned char bytes[4]; } thing; thing.a = float_variable; memcpy(bytes_temp, thing.bytes, 4); } Or to really hack it: void float2Bytes(byte bytes_temp[4],float float_variable){ memcpy(bytes_temp, (unsigned char*) (&float_variable), 4); } Note - in either case I make sure to copy the data to the location given as the input parameter. This is crucial, as local variables will not exist after you return (alt...