Python bytearray()

In this tutorial, we will learn about the Python bytearray() method with the help of examples.

The bytearray() method returns a bytearray object which is an array of the given bytes.

Example

prime_numbers = [2, 3, 5, 7]

# convert list to bytearray
byte_array = bytearray(prime_numbers)
print(byte_array)

# Output: bytearray(b'\x02\x03\x05\x07')

1. bytearray() Syntax

The syntax of bytearray() method is:

bytearray(]])

bytearray() method returns a bytearray object (i.e. array of bytes) which is mutable (can be modified) sequence of integers in the range 0 <= x < 256.

If you want the immutable version, use the bytes() method.

2. bytearray() Parameters

bytearray() takes three optional parameters:

• source (Optional) – source to initialize the array of bytes.
• encoding (Optional) – if the source is a string, the encoding of the string.
• errors (Optional) – if the source is a string, the action to take when the encoding conversion fails (Read more: String encoding)

The source parameter can be used to initialize the byte array in the following ways:

Type	Description
String	Converts the string to bytes using str.encode() Must also provide encoding and optionally errors
Integer	Creates an array of provided size, all initialized to null
Object	A read-only buffer of the object will be used to initialize the byte array
Iterable	Creates an array of size equal to the iterable count and initialized to the iterable elements Must be iterable of integers between 0 <= x < 256
No source (arguments)	Creates an array of size 0.

3. bytearray() Return Value

The bytearray() method returns an array of bytes of the given size and initialization values.

4. Example 1: Array of bytes from a string

string = "Python is interesting."

# string with encoding 'utf-8'
arr = bytearray(string, 'utf-8')
print(arr)

Output

bytearray(b'Python is interesting.')

5. Example 2: Array of bytes of given integer size

size = 5

arr = bytearray(size)
print(arr)

Output

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

6. Example 3: Array of bytes from an iterable list

rList = [1, 2, 3, 4, 5]

arr = bytearray(rList)
print(arr)

Output

bytearray(b'\x01\x02\x03\x04\x05')