Python bit functions on int (bit_length, to_bytes and from_bytes)

The int type implements the numbers.Integral abstract base class.

1. int.bit_length()
Returns the number of bits required to represent an integer in binary, excluding the sign and leading zeros.

Code to demonstrate

num = 7
print(num.bit_length())

num = -7
print(num.bit_length())

Output:

3
3

2. int.to_bytes(length, byteorder, *, signed=False)
Return an array of bytes representing an integer.If byteorder is “big”, the most significant byte is at the beginning of the byte array. If byteorder is “little”, the most significant byte is at the end of the byte array. The signed argument determines whether two’s complement is used to represent the integer.

# Returns byte representation of 1024 in a
# big endian machine.
print((1024).to_bytes(2, byteorder ='big'))

Output:

b'\x04\x00'

3. int.from_bytes(bytes, byteorder, *, signed=False)
Returns the integer represented by the given array of bytes.

# Returns integer value of '\x00\x10' in big endian machine.
print(int.from_bytes(b'\x00\x10', byteorder ='big'))

Output:

16