Python / Pandas / Bokeh：用數據框中的圖例繪制多行

Question

我試圖將Pandas dataframe繪制到時間序列折線圖中。

當繪制單條線時，我已經能夠使用p.line函數成功地做到這一點，確保將x_axis_type 'datetime' 。

要繪制多條線，我嘗試使用p.multi_line ，效果很好，但我還需要一個圖例，根據這篇文章，不可能在多線圖中添加圖例 ： Bokeh如何在由multi_line創建的圖形中添加圖例方法？

Leo在上面的鏈接中對這個問題的回答看起來很有希望，但是當數據來自數據幀時，我似乎無法弄清楚如何應用它。

有人有提示嗎？

Answer 1

好的，這似乎可行：

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)