用python写一个vbf文件的类

以下是一个可能的实现：

class VbfFile:
    def __init__(self, filename):
        self.filename = filename
        self.header = {}
        self.data_blocks = []
        
        with open(filename, 'rb') as f:
            # Parse header
            self.header['signature'] = f.read(4)
            self.header['version'] = int.from_bytes(f.read(4), byteorder='little')
            self.header['header_size'] = int.from_bytes(f.read(4), byteorder='little')
            self.header['data_size'] = int.from_bytes(f.read(4), byteorder='little')
            self.header['block_size'] = int.from_bytes(f.read(4), byteorder='little')
            self.header['num_blocks'] = int.from_bytes(f.read(2), byteorder='little')
            self.header['reserved'] = f.read(2)
            
            # Parse data blocks
            for i in range(self.header['num_blocks']):
                block = {}
                block['address'] = int.from_bytes(f.read(4), byteorder='little')
                block['length'] = int.from_bytes(f.read(4), byteorder='little')
                block['data'] = f.read(block['length'])
                self.data_blocks.append(block)
    
    def save(self, filename=None):
        if filename is None:
            filename = self.filename
        
        with open(filename, 'wb') as f:
            # Write header
            f.write(self.header['signature'])
            f.write(self.header['version'].to_bytes(4, byteorder='little'))
            f.write(self.header['header_size'].to_bytes(4, byteorder='little'))
            f.write(self.header['data_size'].to_bytes(4, byteorder='little'))
            f.write(self.header['block_size'].to_bytes(4, byteorder='little'))
            f.write(self.header['num_blocks'].to_bytes(2, byteorder='little'))
            f.write(self.header['reserved'])
            
            # Write data blocks
            for block in self.data_blocks:
                f.write(block['address'].to_bytes(4, byteorder='little'))
                f.write(block['length'].to_bytes(4, byteorder='little'))
                f.write(block['data'])
                
    def add_block(self, address, data):
        block = {}
        block['address'] = address
        block['length'] = len(data)
        block['data'] = data
        self.data_blocks.append(block)
        self.header['num_blocks'] += 1
        self.header['data_size'] += len(data)
        
    def remove_block(self, index):
        if index < 0 or index >= len(self.data_blocks):
            raise IndexError('Index out of range')
        block = self.data_blocks.pop(index)
        self.header['num_blocks'] -= 1
        self.header['data_size'] -= block['length']
        
    def modify_block(self, index, data):
        if index < 0 or index >= len(self.data_blocks):
            raise IndexError('Index out of range')
        block = self.data_blocks[index]
        block['length'] = len(data)
        block['data'] = data
        self.header['data_size'] += len(data) - block['length']