What is a Python bytestring?

A Python bytestring is a sequence of bytes. In Python 3, bytestrings are represented using the "bytes" data type. Bytestrings are used to represent binary data that doesn't fit into the Unicode character set, such as images, audio, and video files.

Here are some code examples that demonstrate working with Python bytestrings:

Creating a bytestring

To create a bytestring in Python, we can use the "b" prefix before a string literal.

Example

In this example, we create a bytestring with the contents "This is a bytestring." and assign it to the variable "bytestring". We then print the bytestring to the console. The "b" prefix before the string literal tells Python to interpret the string as a bytestring.

bytestring = b"This is a bytestring."
print(bytestring)

Output

b'This is a bytestring.'

Converting a string to a bytestring

We can convert a regular string to a bytestring using the "encode()" method.

Example

In this example, we have a regular string with the contents "This is a string." and we want to convert it to a bytestring. We use the "encode()" method to convert the string to a bytestring and assign it to the variable "bytestring". We then print the bytestring to the console.

string = "This is a string."
bytestring = string.encode()
print(bytestring)

Output

b'This is a string.'

Converting a bytestring to a string

We can convert a bytestring to a regular string using the "decode()" method.

Example

In this example, we have a bytestring with the contents "This is a bytestring." and we want to convert it to a regular string. We use the "decode()" method to convert the bytestring to a string and assign it to the variable "string". We then print the string to the console.

bytestring = b"This is a bytestring."
string = bytestring.decode()
print(string)

Output

This is a bytestring.

Working with bytestring methods

Bytestrings have many methods that are similar to regular strings. Here's an example of using the "startswith()" method with a bytestring:

Example

bytestring = b"This is a bytestring."
if bytestring.startswith(b"This"):
    print("The bytestring starts with 'This'")
else:
    print("The bytestring doesn't start with 'This'")

Output

The bytestring starts with 'This'

Writing and reading bytestrings to a file

We can write bytestrings to a file using the "wb" mode, and read them back using the "rb" mode.

Example

In this example, we first write the bytestring to a file called "bytestring.txt" using the "wb" mode. We then open the file again using the "rb" mode and read the contents back into a variable called "read_bytestring". We then print the bytestring to the console.

bytestring = b"This is a bytestring."
with open("bytestring.txt", "wb") as file:
    file.write(bytestring)
with open("bytestring.txt", "rb") as file:
    read_bytestring = file.read()
    print(read_bytestring)

Output

b'This is a bytestring.'

Concatenating bytestrings

We can concatenate bytestrings using the "+" operator. Here's an example:

Example

In this example, we have two bytestrings and we want to concatenate them. We use the "+" operator to concatenate the bytestrings and assign the result to a new variable called "concatenated_bytestring". We then print the concatenated bytestring to the console.

bytestring1 = b"This is the first bytestring. "
bytestring2 = b"This is the second bytestring."
concatenated_bytestring = bytestring1 + bytestring2
print(concatenated_bytestring)

Output

b'This is the first bytestring. This is the second bytestring.'