byte oriented programming

Question 1

~240

Answer 1

-241

Question 2

how to get complimentary

Answer 2

bit(~0b11110000&0b11111111)

(1 &laquo_space;a.bit_length()) - 1 - a

Question 3

get number of bits for integer

Answer 3

int(256).bit_length()

Question 4

int to bytes

Answer 4

int(0xcafebabe).to_bytes(length=4, byteorder=’big’)

int(0xcafebabe).to_bytes(length=4, byteorder=’little’)

Question 5

get native byteorder

Answer 5

sys.byteorder

Question 6

get int from bytes

Answer 6

int.from_bytes(bytes, byteorder=”little”)

Question 7

byte string from literal

Answer 7

b’some string’

Question 8

create bytes with several elements

Answer 8

bytes(5)

Question 9

create bytes from iterables of integers

Answer 9

bytes([55,34,22,254])

Question 10

create bytes from string

Answer 10

bytes(string, encoding=”utf16”)

Question 11

create bytes from hex string

Answer 11

bytes.fromhex(‘543433434fb0323’)

Question 12

create mutable bytearray

Answer 12

bytearray()

Question 13

module for working with C structures

Answer 13

struct

Question 14

get items from bytes

Answer 14

struct.unpack_from(‘@fffHHH’, buffer)

@ - native byte order

Question 15

get iterables of items from bytes

Answer 15

struct.iter_unpack(‘@3f3H, buffer’)

Question 16

get hex representation of string

Answer 16

binascii.hexlify(string)

Question 17

create memoryview

Answer 17

memoryview(bytes)

Question 18

interpreter the memoryview

Answer 18

mem[12:18].cast(‘H’).tolist()

Question 19

get memorymap file

Answer 19

with mmap.mmap(file.fileno(), 0 , access=mmap.ACCESS_READ ) as buffer: