Python bokeh AttributeError: unexpected attribute 'legend_label' to Line, possible attributes are js_event_callbacks

问题再现

在运行bokeh官方文档中的以下脚本时出现错误。

from bokeh.plotting import figure, output_file, show

# prepare some data
x = [1, 2, 3, 4, 5]
y = [6, 7, 2, 4, 5]

# output to static HTML file
output_file("lines.html")

# create a new plot with a title and axis labels
p = figure(title="simple line example", x_axis_label='x', y_axis_label='y')

# add a line renderer with legend and line thickness
p.line(x, y, legend_label="Temp.", line_width=2)

# show the results
show(p)

错误：

AttributeError: unexpected attribute 'legend_label' to Line, possible attributes are js_event_callbacks, js_property_callbacks, line_alpha, line_cap, line_color, line_dash, line_dash_offset, line_join, line_width, name, subscribed_events, tags, x or y

原因

查找后发现是版本问题 legend_label 是在Bokeh 1.4中才有， 使用 pip list命令得知当前版本是1.0.4

参考：
https://stackoverflow.com/questions/60610367/stacked-bar-charts-bokeh-attribute-error

解决

1. 升级bokeh版本 pip install --upgrade bokeh
2. 依然原来版本中这个legend_label改为legend