Python 3 - Bytes

byte

• 8-bit integer, in the range 0 to 255
• raw, no meaning; meaning depend on encoding.

Immutable vs Mutable

• bytes is an immutable array of bytes (PyString)
• bytearray is a mutable array of bytes (PyBytes)
• memoryview is a bytes view on another object (PyMemory)

bytes literal: b'...'

• str objects: hold character data
• bytes objects: hold raw bytes

Indexing returns a integer:

>>> a = b'asdf'
>>> a
b'asdf'
>>> a[0]
97

while str returns a character:

>>> b = 'asdf'
>>> b
'asdf'
>>> b[0]
'a'

• Assigning or comparing an object that is not an integer to an element causes a TypeError exception.
• Assigning an element to a value outside the range 0 to 255 causes a ValueError exception.