How Python simulates the bit fields of C language

How Python simulates the bit fields of C language

In Python, you can use the struct module to simulate bit fields in C language.

First, you need to import the structure module. The following code can be used:

import struct

Then, you can define a structure containing bit fields. In a structure, you can use "<" or ">" to indicate byte order. Next, you can use ":" to specify the length of the bit field. For example, the following code defines a structure containing two bit fields:

class MyStruct(struct.Struct):  
    _fields_ = [  
        ('field1', '2b'),  # 2位位域  
        ('field2', '6b')   # 6位位域  
    ]

In this structure, field12 bits are occupied and field26 bits are occupied. Note that the order of the bit fields is from low-order to high-order.

Next, you can create an instance and set the value of the bitfield:

my_struct = MyStruct()  
my_struct.field1 = 3  
my_struct.field2 = 63

You can use the following code to get the value of a bit field:

print(my_struct.field1)  # 输出 3  
print(my_struct.field2)  # 输出 63

You can also use the following code to convert the value of a structure to bytes:

bytes_value = my_struct.to_bytes()  
print(bytes_value)  # 输出 b'\x03\x3f'

The bytes can be converted back into a structure using the following code:

new_my_struct = MyStruct.from_bytes(bytes_value)  
print(new_my_struct.field1)  # 输出 3  
print(new_my_struct.field2)  # 输出 63

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