在末尾识别连续的非 nan 值

如何解决在末尾识别连续的非 nan 值

如何获取表中连续非 NaN 值的最后一部分？例如：

   col
0  1.0
1  2.0
2  NaN
3  NaN
4  3.0
5  NaN
6  4.0
7  5.0
8  6.0

想要的结果：

   col
6  4.0
7  5.0
8  6.0

我的解决方案：

df[df.col[::-1].isna().cumsum()[::-1].eq(0)]

解决方法

试试这个：

last_index = df[df.col.isna()].index[-1]
df.iloc[last_index + 1:]

输出：

    col
6   4.0
7   5.0
8   6.0

,

这是您可以执行此操作的另一种方法 -

last_index = np.where(df.col.isna())[0][-1]
df.iloc[last_index+1:]

df[df.loc[::-1,'col'].isna().cumsum()[::-1]==0]

,

这对我有用：

from urllib.request import urlopen
from bs4 import BeautifulSoup
import base64
import pytesseract as pyt
import requests
from PIL import Image
import matplotlib.pyplot as ptl
import numpy as np

pyt.pytesseract.tesseract_cmd = r'C:\Program Files\Tesseract-OCR\tesseract.exe'


login_url = 'http://www.root-me.org/?page=login&lang=fr'
payload = {
          'var_login': 'email','password': 'pass'
           }

with requests.Session() as s:
    response = requests.post(login_url,payload)
    scrap_url= urlopen('http://challenge01.root-me.org/programmation/ch8/')
    soup = BeautifulSoup(scrap_url)
    img = soup.find('img')['src'].split(',')[1]
    with open('captcha.png','wb') as guardar:
        decodificar = base64.b64decode(img)
        guardar.write(decodificar)
    

leer_img = Image.open('captcha.png','r')
ptl.imshow(np.asarray(leer_img))
texto_captcha = pyt.image_to_string(leer_img)
print(texto_captcha)