Python program structure [2], class/class, built-in class bytes and ByteArray

built-in classes bytes and bytearray/built-in type bytes and ByteArray

About built-in classes

Python's built-in class bytes has the following main points:

Class bytes ([source[, encoding[, errors]])

Return a new "bytes" object, which is an immutable sequence of integers in the range 0 <= x < 256. Bytes is a immutable version of Bytearray–it has the same non-mutating methods and the same indexing and slicing Behav Ior.

Accordingly, constructor arguments is interpreted as for ByteArray ().

1. The return value is a new non-modifiable byte array, each number element must be within the range of 0-255, is the ByteArray function has the same behavior, the difference is only the returned byte array is not modifiable ;

2. Returns a byte array with a length of 0 when none of the 3 parameters are transmitted;

3. The encoding parameter must also be provided when the source parameter is a string, and the function converts the string to a byte array using the Str.encode method;

4. When the source parameter is an integer, returns an empty byte array of the length specified by the integer;

5. When the source parameter is a type object that implements the buffer interface, the read-only method is used to return the bytes to the byte array;

6. When the source parameter is an iterative object, the elements of the iteration object must conform to 0 <= x < 256 so that it can be initialized into the array;

7. The returned array cannot be modified.

>>> bytes (1)  b'\x00'  >>> bytes ([1, 2, 3])  b'\x01\x02\x03'  

The biggest difference between bytes and ByteArray is that bytes-generated objects are not modifiable.

1s ='@MOVE \ r \ n'2 3m = ByteArray (S, encoding='ASCII')4x = bytes (S, encoding='ASCII')5 6M[0] = 657 Try:8X[0] = 659 except:Ten     Pass One  A Print(m, X, sep='\ n')

From the output you can see that M is modified and X has not been modified

ByteArray (b'amove\r\n')  b'@MOVE \ r \ n'  

Related reading

1. About the built-in class

Reference Links

Http://www.cnblogs.com/sesshoumaru/p/5980090.html

Python program structure [2], class/class, built-in class bytes and ByteArray