Python Learning note 015--sequence (byte array bytearray)

1 sequence

Common sequences are: List tuple str bytes (byte string) ByteArray

2-byte array ByteArray

A variable sequence of bytes, equivalent to a variable version of bytes.

3 Creating a function ByteArray

To create a method rule for a ByteArray object

ByteArray () ByteArray (integer-N) bytearray (integer-iterated object)
ByteArray (b ' string ')
ByteArray (string, encoding='utf-8')

Example:

>>>ByteArray () ByteArray (b"')>>> ByteArray ([a]) ByteArray (b'\x01\x02\x03')>>> ByteArray (["a","b","C"]) Traceback (most recent): File"<stdin>", Line 1,inch<module>Typeerror:an integer isRequired>>> ByteArray (3) ByteArray (b'\x00\x00\x00')>>> ByteArray ("ABC", encoding="Utf-8") ByteArray (b'ABC')>>> ByteArray ("ABC") Traceback (most recent): File"<stdin>", Line 1,inch<module>typeerror:string argument without an encoding

4 arithmetic operations

byte arrays operate in a similar way to lists

+ +   =   *   *= comparison operation  :< <= > >= = = =in/not in/slice Slice

Example

>>> a = ByteArray (b"ABCDE")>>>A[0]97>>>Print(a) ByteArray (b'ABCDE')>>> a[1:] = ByteArray (b'BCDE')#Slice Assignment>>>Abytearray (b'ABCDE')>>> A[0] = 0x41#single-element assignment, the ASCII value of a 0x41>>>Abytearray (b'ABCDE')>>> B = Bytes (a)#to convert a byte array to a byte string>>>BB'ABCDE'>>> C = ByteArray (b)#to turn a byte string into a byte array>>>CByteArray (b'ABCDE')

5 ByteArray Common methods

Method	Description
BA represents a byte array
Ba.clear ()	Empty
Ba.append (N)	Append one byte (n is an integer of 0~255)
Ba.remove (value)	Deletes the first occurrence of the byte, or generates a valueerror error if none
Ba.reverse ()	BYTE order reversal
Ba.decode (encoding= ' utf-8 ')	Convert to String
Ba.find (sub[, Start[,end]])	Find sub-byte string

6 The difference between bytes, ByteArray and str

Byte string bytes, byte array bytearray is a sequence of binary data, each of which consists of 8bit binary (with 1byte, the same 2-bit 16 binary number, and 0~255).

The number of bytes in the computer's language, the strings are human languages, and they form a one by one correspondence between the coded tables.

The smallest ASCII encoding table only needs one byte, and only occupies the [31,127] code bit;

STR storage Unicodel 6 characters (0~65535)

Bytes/bytearry = Str.encode (encoding="utf-8"= Bytes/bytearray.decode (encoding ="utf-8")

Encode: Encoding, decode: decoding

Python Learning note 015--sequence (byte array bytearray)