使用Python和Cartopy按值填充美国县？

pip install cartopy

import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.io.shapereader as shpreader

shapefile_path = 'path/to/us_counties.shp'

# 创建一个记录县值的字典
county_values = {}

# 读取shapefile文件
shape_records = shpreader.Reader(shapefile_path).records()

# 提取每个县的值，并将其存储在county_values字典中
for record in shape_records:
    county_fips = record.attributes['FIPS']
    value = get_value_for_county(county_fips)  # 根据具体情况获取每个县的值
    county_values[county_fips] = value

# 创建一个地图对象
fig = plt.figure(figsize=(10, 6))
ax = fig.add_subplot(1, 1, 1, projection=ccrs.PlateCarree())

# 加载美国地图
ax.add_geometries(
    shpreader.Reader(shapefile_path).geometries(),
    ccrs.PlateCarree(),
    edgecolor='black',
    facecolor='none'
)

# 按值填充每个县
for county in shpreader.Reader(shapefile_path).records():
    county_fips = county.attributes['FIPS']
    value = county_values.get(county_fips, 0)  # 如果没有值，默认为0
    ax.add_geometries(
        [county.geometry],
        ccrs.PlateCarree(),
        edgecolor='black',
        facecolor=get_color_based_on_value(value)  # 根据值获取对应的颜色，具体根据情况自定义
    )

# 添加标题和颜色图例
ax.set_title("按值填充美国县")
plt.colorbar(plt.cm.ScalarMappable(norm=None, cmap='coolwarm'), ax=ax, shrink=0.6, label='值')

# 显示地图
plt.show()