Python / Pandas / Bokeh：用数据框中的图例绘制多行

Question

我试图将Pandas dataframe绘制到时间序列折线图中。

当绘制单条线时，我已经能够使用p.line函数成功地做到这一点，确保将x_axis_type 'datetime' 。

要绘制多条线，我尝试使用p.multi_line ，效果很好，但我还需要一个图例，根据这篇文章，不可能在多线图中添加图例 ： Bokeh如何在由multi_line创建的图形中添加图例方法？

Leo在上面的链接中对这个问题的回答看起来很有希望，但是当数据来自数据帧时，我似乎无法弄清楚如何应用它。

有人有提示吗？

Answer 1

好的，这似乎可行：

from bokeh.plotting import figure, output_file, save
from bokeh.models import ColumnDataSource
import pandas as pd
from pandas import HDFStore
from bokeh.palettes import Spectral11

# imports data to dataframe from our storage hdf5 file
# our index column has no name, so this is assigned a name so it can be
# referenced to for plotting
store = pd.HDFStore('<file location>')
df = pd.DataFrame(store['d1'])
df = df.rename_axis('Time')

#the number of columns is the number of lines that we will make
numlines = len(df.columns)

#import color pallet
mypalette = Spectral11[0:numlines]

# remove unwanted columns
col_list = ['Column A', 'Column B']
df = df[col_list]

# make a list of our columns
col = []
[col.append(i) for i in df.columns]

# make the figure, 
p = figure(x_axis_type="datetime", title="<title>", width = 800, height = 450)
p.xaxis.axis_label = 'Date'
p.yaxis.axis_label = '<units>'

# loop through our columns and colours
for (columnnames, colore) in zip(col, mypalette):
    p.line(df.index, df[columnnames], legend = columnnames, color = colore )

# creates an output file 
output_file('<output location>')

#save the plot
save(p)