在matplotlib中自定义次要y轴上的y标签，以使用逗号将其格式设置为千位

import matplotlib.pyplot as plt
import matplotlib.ticker as ticker

fig, ax1 = plt.subplots()
ax2 = ax1.twinx()

def format_func(value, tick_number):
    return "{:,.0f}".format(value)

ax2.yaxis.set_major_locator(ticker.MaxNLocator(nbins=5))
ax2.yaxis.set_major_formatter(ticker.FuncFormatter(format_func))

ax1.plot(x, y1, color='blue', label='Primary Y-axis')
ax2.plot(x, y2, color='red', label='Secondary Y-axis')

ax1.legend(loc='upper left')
ax2.legend(loc='upper right')
ax1.set_xlabel('X-axis')
ax1.set_ylabel('Primary Y-axis')
ax2.set_ylabel('Secondary Y-axis')

plt.show()