Python bytearray() Builtin Function

Python bytearray

Python bytearray() builtin function is used to create a bytearray object with from given data source or of given specific size.

In this tutorial, we will learn about the syntax of Python bytearray() function, and learn how to use this function with the help of examples.

Syntax

The syntax of bytearray() function is

bytearray(]])

where

Parameter	Required/Optional	Description
source	Optional	The source can be an integer, string, iterable or an object that conforms to the buffer interface.
encoding	Optional. Required if `source` is string,	The encoding of the the string (if `source` is string).
errors	Optional	The action to take if encoding fails.

Returns

The function returns object of class type bytearray.

Examples

1 bytearraystring, encoding

In this example, we will give string value for source parameter and ‘utf-8’ for encoding, to the bytearray() function. The bytearray() function returns a bytearray object created from the string and encoding data.

Python Program

source = "helloworld"
encoding = 'utf-8'
bytearray1 = bytearray(source, encoding)
print(f'Return Value: {bytearray1}')

Output

Return Value: bytearray(b'helloworld')

In this example, we will give string as source to the bytearray() function, but without encoding parameter.

Python Program

source = "helloworld"
bytearray1 = bytearray(source)
print(f'Return Value: {bytearray1}')

Output

Traceback (most recent call last):
  File "d:/workspace/python/example.py", line 2, in <module>
    bytearray1 = bytearray(source)
TypeError: string argument without an encoding

2 bytearrayinteger

In this example, we will give integer for source parameter to the bytearray() function. The bytearray() function returns a bytearray object with size equal to given integer, and each item in the byte array as \x00.

Python Program

source = 6
bytearray1 = bytearray(source)
print(f'Return Value: {bytearray1}')

Output

Return Value: bytearray(b'\x00\x00\x00\x00\x00\x00')

3 bytearraylist

In this example, we will give list of integers as source to the bytearray() function. The bytearray() function returns a bytearray object created from the list of integers. The values in the list should be only integers with values ranging from 0 to 255.

Python Program

source = [65, 66, 67, 68]
bytearray1 = bytearray(source)
print(f'Return Value: {bytearray1}')

Output

Return Value: bytearray(b'ABCD')

If any integer value in the list is out of range for a byte, then bytearray() throws ValueError, as shown in in the following program.

Python Program

source = [65, 66, 67, 68, 362]
bytearray1 = bytearray(source)
print(f'Return Value: {bytearray1}')

Output

Traceback (most recent call last):
  File "d:/workspace/python/example.py", line 2, in <module>
    bytearray1 = bytearray(source)
ValueError: byte must be in range(0, 256)

Conclusion

In this Python Tutorial, we have learnt the syntax of Python bytearray() builtin function, and also learned how to use this function, with the help of Python example programs.