问如何使用matplotlib自定义甘特图，并在图形上显示表示当前时间的垂直线？

EN

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
from datetime import datetime
import pandas as pd
import math
# % matplotlib inline

def timestr_to_num(timestr):
    return mdates.date2num(datetime.strptime('0' + timestr if timestr[1] == ':' else timestr, '%I:%M:%S %p'))

plt.style.use('ggplot')
# df = pd.read_csv('zpp00141_new.csv')
columns = ['Operation short text', 'Operation/Activity', 'Earl. start / time', 'Latest finish / time']
rows = [['Mount right racks', '0250', '7:00:00 AM', '9:22:00 AM'],
        ['Mount right side motion unit carriage', '0251', '9:22:00 AM', '10:30:00 AM'],
        ['Mount left side motion unit carriage', '0252', '10:30:00 AM', '11:17:00 AM'],
        ['Install motion unit complete', '0253', '11:17:00 AM', '1:01:00 PM'],
        ['Move machine to next step + EPA', '0254', '1:01:00 PM', '3:30:00 PM'],
        ['Mount Left Racks', '0200', '7:00:00 AM', '9:12:00 AM'],
        ['Mount cable motor & Lubricate guide carr', '0201', '9:12:00 AM', '9:44:00 AM'],
        ['Mount suction components', '0202', '9:44:00 AM', '11:04:00 AM'],
        ['Mount extraction', '0203', '11:04:00 AM', '12:34:00 PM'],
        ['Mount temporary diamond plates', '0204', '12:34:00 PM', '1:04:00 PM'],
        ['Mount piping inside', '0205', '1:04:00 PM', '1:44:00 PM'],
        ['Move Machine to next step + EPA', '0206', '1:44:00 PM', '3:30:00 PM']]
df = pd.DataFrame(data=rows, columns=columns)
df.rename(columns={"Earl. start / time": "start", "Latest finish / time": "finish"}, inplace=True)

df['Operation/Activity'] = df['Operation/Activity'].astype(int)
df.sort_values('Operation/Activity', ascending=True, inplace=True, ignore_index=True)

fig, ax = plt.subplots(figsize=(10, 5))

#colors = plt.cm.tab10.colors  # get a list of 10 colors
cmap = plt.cm.get_cmap('plasma_r')
colors = [cmap(i/9) for i in range(10)]   # get a list of 10 colors

previous_start = math.inf  # 'previous_start' helps to indicate we're starting again from the left
color_start = 0
for row in df.itertuples():
    left = timestr_to_num(row.start)
    right = timestr_to_num(row.finish)
    if left <= previous_start:
        color_start = row.Index
    ax.barh(row.Index, left=left, width=right - left, height=1, color=colors[(row.Index - color_start) % len(colors)])
    previous_start = left
ax.set_xlim(timestr_to_num('7:00:00 AM'), timestr_to_num('4:30:00 PM'))
ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M'))  # display ticks as hours and minutes
ax.xaxis.set_major_locator(mdates.HourLocator(interval=1))  # set a tick every hour
ax.set_xlabel('Time')
ax.set_ylabel('Operation')
ax.set_ylim(len(df), -1)  # set the limits and reverse the order
ax.set_yticks(range(len(df)))
# ax.set_yticklabels(list(df['Operation/Activity']))
ax.set_yticklabels(list(df['Operation short text']))

now = datetime.now().strftime('%I:%M:%S %p')
ax.axvline(x=timestr_to_num(now),color='r')

plt.tight_layout()
plt.show()

now = datetime.now()
now = now.strftime('%I:%M:%S %p')
plt.axvline(x=timestr_to_num(now),color='r')