将带有逗号的数据框中的列转换为数字数据以进行绘图

Question

I'm new in the world of plotting in Python I started learning today doing a mini project by my own, I tried to scrape data and represent here's my code:

import requests
import pandas as pd
from pandas import DataFrame
import numpy as np
import bs4
from bs4 import BeautifulSoup
import matplotlib.pyplot as plot

# Getting the HTML page
URL = "https://www.worldometers.info/coronavirus/#countries"
pag_html = requests.get(URL).text

# Extracting data with BeautifulSoup.
soup = BeautifulSoup(pag_html, 'html.parser')

tabla = soup.find("table", id="main_table_countries_today")

datos_tabla = tabla.tbody.find_all("tr")

Lista = []

for x in range(len(datos_tabla)):
  values = [j.string for j in datos_tabla[x].find_all('td')]
  Lista.append(values)


df = pd.DataFrame(Lista).iloc[7: , 1:9]
nombre_columna = ["Pais", "Casos totales", "Nuevos Casos", "Muertes totales", "Nuevas Muertes", "Total Recuperados", "Nuevos Recuperados", "Activos"]
df.columns = nombre_columna



df.plot(x="Pais", y="Casos totales", kind ="barh")
plot.show()

The error it's giving me is: "TypeError: no numeric data to plot" I understand that this error is because the column "Casos totales" is a string not a float. I tried to convert the columns of my Dataframe into floats, but there's no way I got error from everywhere. Does anyone have any idea how can I represent my DataFrame?

Thanks.

Answer 1

After running the script, as you say the column "Casos Totales" is being interpreted as string due to the commas in the values. You can change this using .str.replace(',','') and then .astype(float) , right after renaming the column names in your dataframe:

df['Casos totales'] = df['Casos totales'].str.replace(',','').astype(float)


df.plot(x="Pais", y="Casos totales", kind ="barh")
plot.show()

And this plots the graph (although the visualization is quite poor, but that's another story)