What is byte array in python

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')

bytearray() Syntax

The syntax of bytearray() method is:

bytearray([source[, encoding[, errors]]])

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.

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:

bytearray() Return Value

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

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.')

Example 2: Array of bytes of given integer size

size = 5

arr = bytearray(size)
print(arr)

Output

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

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')

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"

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 = 3

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.

arr1 = bytearray(b"abcd")

for value in arr1:

    print(value)

arr2 = bytearray(b"aaaacccc")

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.

list = [1, 2, 3, 4]

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 = bytearray()

print(array)

Output:

bytearray(b'')

What is a byte array?

What does byte mean in Python?

What is the difference between byte and byte array in Python?