如何在pyqtgraph PlotWidget中添加字符串轴

import pyqtgraph as pg
from pyqtgraph import AxisItem

plot = pg.PlotWidget()

axis = AxisItem(orientation='bottom')  # 或者 orientation='left'

axis.setTicks([[(1, 'A'), (2, 'B'), (3, 'C'), (4, 'D')]])  # 设置刻度和对应的标签

plot.getPlotItem().axes['bottom']['item'] = axis  # 添加到底部（x轴）
# 或者
plot.getPlotItem().axes['left']['item'] = axis  # 添加到左侧（y轴）

import pyqtgraph as pg
from pyqtgraph import AxisItem

# 创建PlotWidget对象
plot = pg.PlotWidget()

# 创建AxisItem对象
axis = AxisItem(orientation='bottom')

# 设置字符串轴的刻度和标签
axis.setTicks([[(1, 'A'), (2, 'B'), (3, 'C'), (4, 'D')]])

# 将AxisItem对象添加到PlotWidget中的底部（x轴）
plot.getPlotItem().axes['bottom']['item'] = axis