How to write a program in Python to obtain map tiles in Baidu Map API?

How to write a program in Python to obtain the map tiles in Baidu Map API?

Map tiles are the basic elements that make up a map. By dividing the map into small independent images, faster map loading and display can be achieved. Baidu Map API provides rich map tile data. This article will introduce how to use Python to obtain map tiles in Baidu Map API and give code examples.

Obtaining the map tiles of Baidu Map API requires the key (ak) provided by the interface. Therefore, you first need to apply for an account on the Baidu Map Open Platform and create an application to obtain ak. After creating the application, save ak for subsequent use.

The key steps to obtain map tiles in Python are as follows:

1. Import the required libraries:

import requests
import math
import os

2. Definition of obtaining map tiles Function:

def get_map_tile(x, y, zoom, ak, save_path):
    url = f"http://api.map.baidu.com/customimage/tile?x={x}&y={y}&z={zoom}&ak={ak}"
    response = requests.get(url)
    if response.status_code == 200:
        tile_path = os.path.join(save_path, f"{zoom}_{x}_{y}.png")
        with open(tile_path, "wb") as f:
            f.write(response.content)
        print(f"Successfully saved tile {zoom}/{x}/{y}")
    else:
        print(f"Failed to get tile {zoom}/{x}/{y}")

3. Define the function to obtain the map coordinate range:

def get_tile_range(lon1, lat1, lon2, lat2, zoom):
    tile_x1 = math.floor((lon1 + 180) / 360 * pow(2, zoom))
    tile_y1 = math.floor((1 - math.log(math.tan(math.radians(lat1)) + 1 / math.cos(math.radians(lat1))) / math.pi) / 2 * pow(2, zoom))
    tile_x2 = math.floor((lon2 + 180) / 360 * pow(2, zoom))
    tile_y2 = math.floor((1 - math.log(math.tan(math.radians(lat2)) + 1 / math.cos(math.radians(lat2))) / math.pi) / 2 * pow(2, zoom))
    return tile_x1, tile_y1, tile_x2, tile_y2

4. Define the main function to execute the logic of obtaining the map tiles :

def main():
    # 设置参数
    ak = "your_baidu_map_ak"
    zoom = 10
    lon1, lat1 = 116.3000, 39.9000  # 左上角经纬度
    lon2, lat2 = 116.6000, 39.7000  # 右下角经纬度
    save_path = "./tiles"  # 保存路径

    # 创建保存路径
    os.makedirs(save_path, exist_ok=True)

    # 获取瓦片范围
    tile_x1, tile_y1, tile_x2, tile_y2 = get_tile_range(lon1, lat1, lon2, lat2, zoom)

    # 循环获取所有瓦片
    for x in range(tile_x1, tile_x2 + 1):
        for y in range(tile_y1, tile_y2 + 1):
            get_map_tile(x, y, zoom, ak, save_path)

    print("All tiles are successfully saved!")

if __name__ == "__main__":
    main()

In the code example, the get_map_tile function is used to obtain the map tile with specified coordinates and zoom level and save it to the specified path. get_tile_rangeThe function is used to calculate the tile range that needs to be obtained based on the given map coordinate range and zoom level.

In the main function, the parameters required to obtain the map tiles are first set, such as ak, zoom level and map coordinate range. Then, a directory is created to save the map tiles. Next, call the get_map_tile function cyclically according to the coordinates of the tile range to obtain all map tiles. Finally, output a prompt message indicating that all map tiles have been successfully saved.

Through the above code, we can easily use Python to obtain the map tiles in Baidu Map API. You can adjust the parameters to obtain map tiles of different areas and zoom levels according to your own needs. The obtained map tiles can be used for display, analysis and other geographical information processing application scenarios.

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