从Matplotlib图例中排除Cartopy元素

import matplotlib.pyplot as plt
import cartopy.crs as ccrs

proj = ccrs.PlateCarree()

fig, ax = plt.subplots(subplot_kw={'projection': proj})

ax.plot([-74, -70, -75], [40, 42, 38], 'bo', transform=proj)

from matplotlib.legend_handler import HandlerBase

class ExcludeCartopyHandler(HandlerBase):
    def create_artists(self, legend, orig_handle,
                       xdescent, ydescent, width, height, fontsize, trans):
        return []

ax.legend([ax.plot([], [], 'bo', label='Data')[0]], ['Data'], handler_map={type(ax.plot([], [], 'bo')).__name__: ExcludeCartopyHandler()})