用protobuf 解析 mvt的代码

以下是一个使用protobuf解析MVT的示例代码：

import gzip
import struct
import zlib

import mercantile
import vector_tile_pb2


def decode_varint(data):
    value, shift = 0, 0
    while True:
        byte = data.read(1)[0]
        value |= (byte & 0x7f) << shift
        shift += 7
        if not byte & 0x80:
            break
    return value


def decompress(data):
    if data[:2] == b'\x1f\x8b':
        return zlib.decompress(data, 16 + zlib.MAX_WBITS)
    return data


def parse_feature(data):
    feature = vector_tile_pb2.Tile.Feature()
    feature.ParseFromString(data)
    return feature


def parse_layer(data):
    layer = vector_tile_pb2.Tile.Layer()
    layer.ParseFromString(data)
    return layer


def parse_geometry(data, geometry_type):
    geometry = []
    x, y = 0, 0
    for i in range(len(data)):
        dx, dy = data[i], data[i + 1]
        x += dx
        y += dy
        if geometry_type == 1:
            geometry.append((x, y))
        elif geometry_type == 2:
            geometry.append((x, y))
            x, y = 0, 0
        elif geometry_type == 3:
            geometry.append((x, y))
            x, y = data[i + 2], data[i + 3]
            i += 2
        else:
            raise ValueError('Invalid geometry type')
    return geometry


def parse_mvt(data):
    tile = vector_tile_pb2.Tile()
    tile.ParseFromString(decompress(data))
    result = {}
    for layer in tile.layers:
        layer_name = layer.name
        layer_extent = layer.extent
        layer_features = []
        for feature in layer.features:
            feature_type = feature.type
            feature_geometry = parse_geometry(feature.geometry, feature_type)
            feature_tags = feature.tags
            feature_properties = {}
            for i in range(0, len(feature_tags), 2):
                key = layer.keys[feature_tags[i]]
                value = layer.values[feature_tags[i + 1]]
                if value.HasField('stringValue'):
                    feature_properties[key] = value.stringValue
                elif value.HasField('floatValue'):
                    feature_properties[key] = value.floatValue
                elif value.HasField('doubleValue'):
                    feature_properties[key] = value.doubleValue
                elif value.HasField('intValue'):
                    feature_properties[key] = value.intValue
                elif value.HasField('uintValue'):
                    feature_properties[key] = value.uintValue
                elif value.HasField('sintValue'):
                    feature_properties[key] = value.sintValue
                elif value.HasField('boolValue'):
                    feature_properties[key] = value.boolValue
            layer_features.append({
                'geometry': feature_geometry,
                'properties': feature_properties
            })
        result[layer_name] = {
            'extent': layer_extent,
            'features': layer_features
        }
    return result


if __name__ == '__main__':
    with open('data.mvt', 'rb') as f:
        data = f.read()
    result = parse_mvt(data)
    print(result)

此代码将MVT数据解析为Python字典，并提取每个图层的范围、要素和属性。可以根据需要修改代码以提取其他信息。