Python | bytearray() function

bytearray() method returns a bytearray object which is an array of given bytes. It gives a mutable sequence of integers in the range 0 <= x < 256.

Syntax:

bytearray(source, encoding, errors)

Parameters:

source[optional]: Initializes the array of bytes
encoding[optional]: Encoding of the string
errors[optional]: Takes action when encoding fails

Returns: Returns an array of bytes of the given size.

source parameter can be used to initialize the array in few different ways. Let’s discuss each one by one with help of examples.

Code #1: If a string, must provided encoding and errors parameters, bytearray() converts the string to bytes using str.encode()

str = "Geeksforgeeks"

# encoding the string with unicode 8 and 16
array1 = bytearray(str, 'utf-8')
array2 = bytearray(str, 'utf-16')

print(array1)
print(array2)

Output:

bytearray(b'Geeksforgeeks')
bytearray(b'\xff\xfeG\x00e\x00e\x00k\x00s\x00f\x00o\x00r\x00g\x00e\x00e\x00k\x00s\x00')

Code #2: If an integer, creates an array of that size and initialized with null bytes.

# size of array
size = 3

# will create an array of given size
# and initialize with null bytes
array1 = bytearray(size)

print(array1)

Output:

bytearray(b'\x00\x00\x00')

Code #3: If an Object, read-only buffer will be used to initialize the bytes array.

# Creates bytearray from byte literal
arr1 = bytearray(b"abcd")

# iterating the value
for value in arr1:
    print(value)

# Create a bytearray object
arr2 = bytearray(b"aaaacccc")

# count bytes from the buffer
print("Count of c is:", arr2.count(b"c"))

Output:

97
98
99
100
Count of c is: 4

Code #4: If an Iterable(range 0<= x < 256), used as the initial contents of an array.

# simple list of integers
list = [1, 2, 3, 4]

# iterable as source
array = bytearray(list)

print(array)
print("Count of bytes:", len(array))

Output:

bytearray(b'\x01\x02\x03\x04')
Count of bytes: 4

Code #5: If No source, an array of size 0 is created.

# array of size o will be created

# iterable as source
array = bytearray()

print(array)

Output:

bytearray(b'')