Python3 Bytes API
Introduction
The bytes
type in Python3 is used to store a sequence of bytes. It is immutable and represents a sequence of integers in the range 0-255. The bytes
type is commonly used to handle binary data, such as reading/writing files or working with network protocols. In this article, we will explore the bytes
API in Python3 and see how it can be used in various scenarios.
Creating Bytes Objects
There are several ways to create a bytes
object in Python3:
- Using a byte literal: Bytes literals are represented by a leading
b
orB
character followed by a string of ASCII characters or escape sequences.
b = b'This is a bytes object'
- Using the
bytes
constructor: Thebytes
constructor can be used to create abytes
object from a sequence of integers or an iterable of integers.
b = bytes([65, 66, 67]) # create a bytes object from a list of integers
- Encoding a string: The
encode
method can be used to encode a string into abytes
object using a specific encoding.
b = 'Hello, world!'.encode('utf-8') # encode a string into a bytes object using UTF-8 encoding
Accessing Bytes
Bytes objects can be accessed using the same indexing and slicing techniques as strings. Each byte in the bytes
object can be accessed as an integer in the range 0-255.
b = b'Hello, world!'
print(b[0]) # Output: 72
print(b[7:12]) # Output: b'world'
Modifying Bytes
Since bytes objects are immutable, you cannot modify them directly. However, you can create a new bytes object by concatenating or replacing parts of an existing bytes object.
b1 = b'Hello'
b2 = b'world!'
b3 = b1 + b2 # concatenate two bytes objects
print(b3) # Output: b'Hello, world!'
Converting Bytes to String
To convert a bytes
object to a string, you can use the decode
method and provide the encoding used to encode the bytes.
b = b'Hello, world!'
s = b.decode('utf-8') # decode the bytes using UTF-8 encoding
print(s) # Output: Hello, world!
Common Methods
Bytes objects provide several methods for working with binary data:
len(b)
: Returns the length of the bytes objectb
.b.hex()
: Returns a hexadecimal representation of the bytes object.b.count(sub)
: Returns the number of non-overlapping occurrences ofsub
in the bytes object.b.find(sub)
: Returns the lowest index in the bytes object wheresub
is found, or -1 if it is not found.b.startswith(prefix)
: ReturnsTrue
if the bytes object starts with the specifiedprefix
, otherwiseFalse
.
Conclusion
In this article, we explored the bytes
API in Python3. We learned how to create, access, and modify bytes objects. We also saw how to convert bytes to strings and use common methods provided by the bytes
type. The bytes
type is a powerful tool for working with binary data and is widely used in various applications.