无法将爬虫数据可视化

问题遇到的现象和发生背景

无法将数据可视化

问题相关代码，请勿粘贴截图

#coding=gbk
from selenium import webdriver
import time
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
import re
import pandas as pd
import lxml.html
import xlwt

opt = Options()
opt.add_experimental_option('excludeSwitches', ['enable-automation'])
opt.add_argument('--disable-blink-features')
opt.add_argument('--disable-extensions')
opt.add_argument('--disable-blink-features=AutomationControlled')
driver = webdriver.Chrome(options=opt) # 创建driver对象
driver.get('https://www.acfun.cn/u/1075162') #打开页面
html=driver.page_source #访问整个页面的内容
time.sleep(2)
driver.close() #关闭页面


xp=lxml.html.fromstring(html) #lxml对象
units=xp.xpath('//figcaption') #没有text()
df = pd.DataFrame()


df = None
for u in units:
    w = {}
    w["标题"]=u.xpath('./p [@class="title line"]/text()')[0]
    w["观看与弹幕"]=u.xpath('./p [@class="play-info"]/text()')[0]
    w["日期"] = u.xpath('./p [@class="date"]/text()')[0]
    if w["标题"]==[]:
        print('无')
    df1 = pd.DataFrame([w])
    df = pd.concat([df,df1], ignore_index=True)


    a = re.findall(r'\d+[.]\d+', w["观看与弹幕"])[0]
    print(a)


print(df)


import pandas as pd
df=pd.DataFrame({'观看量':[a]},index=[w["标题"]])
import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif'] = ['SimHei'] # 指定默认字体

df[['观看量']].plot(kind='bar')

plt.show()

运行结果及报错内容

Traceback (most recent call last):
File "C:\Users\86159\AppData\Roaming\JetBrains\PyCharmCE2022.1\scratches\scratch_5.py", line 65, in
df[['观看量']].plot(kind='bar')
File "C:\Users\86159\PycharmProjects\pythonProject9\venv\lib\site-packages\pandas\plotting_core.py", line 972, in call
return plot_backend.plot(data, kind=kind, **kwargs)
File "C:\Users\86159\PycharmProjects\pythonProject9\venv\lib\site-packages\pandas\plotting_matplotlib_init_.py", line 71, in plot
plot_obj.generate()
File "C:\Users\86159\PycharmProjects\pythonProject9\venv\lib\site-packages\pandas\plotting_matplotlib\core.py", line 327, in generate
self._compute_plot_data()
File "C:\Users\86159\PycharmProjects\pythonProject9\venv\lib\site-packages\pandas\plotting_matplotlib\core.py", line 506, in _compute_plot_data
raise TypeError("no numeric data to plot")
TypeError: no numeric data to plot

进程已结束,退出代码1

我的解答思路和尝试过的方法

我想要达到的结果

网上抓下来的数据都是字符串，要转成数字先
把这句
df[['观看量']].plot(kind='bar')
改成
pd.to_numeric(df['观看量']).plot(kind='bar')
再试试