Python

an immutable (can be modified) sequence of integers in the range 0 <=x < 256, the elements of a bytes object cannot be changed

str in Python 2 is byte string

#!/usr/bin/python

d = b'Python How to Program';

print type(d), d #'str', Python How to Program

d2 = bytes([97, 98, 99, 100]); #save whole list as string
print type(d2), str(d2); #'str', [97, 98, 99, 100]
print d2[0]; #[

a mutable (can be modified) sequence of integers in the range 0 <=x < 256

Bytes and bytearrays are an efficient, byte-based form of strings

#!/usr/bin/python

# convert list to bytearray
arr = bytearray([97, 98, 99, 99]);

# convert bytearray to bytes
print bytes(arr); #abcc

# modify elements
arr[0] = 10;

# access element
print arr[0]

# slicing
arr2 = arr[:2];

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys;

# set up default encoding
reload(sys)  # Reload does the trick!
sys.setdefaultencoding('UTF8')
print sys.stdout.encoding;

arr = bytearray("Café", "utf-8");

# convert to string
print type(str(arr)), str(arr);

#convert to unicode
print type(arr.decode('utf-8')), arr.decode('utf-8');

#count
print arr.count(b'a');

# in
if 97 in arr:
    print 'a in arr ...'

# concatenation
print arr+bytearray(b'dddddddd');

#conver to list
print list(arr); #[67, 97, 102, 195, 169]

#append
arr.append(97);

#delete
del arr[:2];

#insert
arr.insert(0, 98);
print arr;

#replace
arr = arr.replace(b'b', b'c');
print arr;