试图绘制timedelta，但yaxis在1e14，想要格式HH：MM：SS

Question

我在x轴（即实际日期）上绘制日期时间，然后在y轴上绘制timedelta，这实际上是时间跨度或时间量。最初我使用yaxis的日期时间，但是我遇到了时间值超过24小时的用例，然后它破坏了代码。所以我必须使用timedelta来适应这些值。但是当我尝试使用plot_date绘制它时，带有timedelta值的yaxis很有趣。

我最初将信息存储在数据框中，然后将值更改为timedelta。这是我输出此图的代码

import datetime as dt
import matplotlib.dates as mdates
import matplotlib
import numpy as np 
import matplotlib.pyplot as plt
import pandas as pd 
import matplotlib as mpl
from matplotlib.backends.backend_pdf import PdfPages

plt.close('all')

#put data into dataframe
location='D:\CAT'
csvpath=location+('\metrics_summaryTEST.csv')
print csvpath
df=pd.read_csv(csvpath)

#setup plot/figure
media = set(df.mediaNumber.values)
num_plots = len(media)
ax = plt.gca()
pdfpath=location+('\metrics_graphs.pdf')
pp = PdfPages(pdfpath)

#declaring some variables
publishTimevals=np.zeros(len(df.publishTime.values),dtype="S20")
xdates=np.zeros(len(df.publishTime.values),dtype="S20")
ytimes=np.zeros(len(df.totalProcessTime.values),dtype="S8")

for f in sorted(media):
    name = f
    plt.figure(f)
    plt.clf()
    color = next(ax._get_lines.color_cycle)
    #PROCESS PUBLISHTIME
    publishTimevals= df.loc[df['mediaNumber']==f,['publishTime']]
    xdates = map(lambda x: mpl.dates.date2num(dt.datetime.strptime(x, '%Y-%m-%d %H:%M')),publishTimevals.publishTime)
    #PROCESS TOTALPROCESSTIME
    totalProcessTimevals= df.loc[df['mediaNumber']==f,['totalProcessTime']]
    ytimes = pd.to_timedelta(totalProcessTimevals.totalProcessTime)
    plt.plot_date(xdates,ytimes,'o-',label='totalProcessTime',color=color)
    print ytimes
    plt.show()
    #format the plot
    plt.gcf().autofmt_xdate()
    plt.xlabel('publishTime')
    plt.ylabel('ProcessTime HH:MM:SS')
    plt.legend(loc=8, bbox_to_anchor=(0.5,-0.3),ncol=3,prop={'size':9})
    ax.grid('on')
    plt.title('%s Processing Time' % (f))
    plt.margins(0.05)
    #plt.grid('on')
    plt.minorticks_on()
    plt.grid(which = 'minor', alpha = 0.3)
    plt.grid(which = 'major', alpha = 0.7)
    plt.show()

有人能指出这里发生了什么吗？