使用for回圈時如何跳過串列中的專案-有解無憂

我試圖跳過串列中的此項，因為它會創建一個例外。我使用了 try 和 except 以及 if 陳述句，但它仍然不起作用，而是忽略了我的 if 陳述句。如果我將 if 陳述句放在例外中，我將無法使用 continue，因為 continue 只能在回圈中作業。有辦法解決嗎？

import time
from selenium import webdriver
import selenium
from selenium.webdriver.chrome import service
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import pandas as pd

#class scraperdata():

ser= Service("C:\Program Files (x86)\chromedriver.exe")
options = webdriver.ChromeOptions()
options.add_experimental_option('excludeSwitches', ['enable-logging'])
driver = webdriver.Chrome(options=options,service=ser)
driver.get('https://soundcloud.com/jujubucks')
print(driver.title)

wait = WebDriverWait(driver,30)

wait.until(EC.element_to_be_clickable((By.ID,"onetrust-accept-btn-handler"))).click()

try:
    i = 1
    for _ in range(32):
        song_contents = driver.find_element(By.XPATH, "//li[@class='soundList__item'][{}]".format(i))
        driver.execute_script("arguments[0].scrollIntoView(true);",song_contents)
        search = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__username')]/span").text
        search_song = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__title')]/span").text
        search_date = song_contents.find_element(By.XPATH, ".//time[contains(@class,'relativeTime')]/span").text
        search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text
        i =1
        if search_plays == False:
            continue
        
        option ={
        'Artist': search, 
        'Song_title': search_song, 
        'Date': search_date,
        'Streams': search_plays
        }
        song_list = []
        song_list.append(option)

        df = pd.DataFrame(song_list)
        print(df)
except Exception:
    pass
driver.quit()

例外

Traceback (most recent call last):
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.9_3.9.2032.0_x64__qbz5n2kfra8p0\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.9_3.9.2032.0_x64__qbz5n2kfra8p0\lib\runpy.py", line 87, in _run_code 
    exec(code, run_globals)
  File "c:\Users\houst\.vscode\extensions\ms-python.python-2021.10.1365161279\pythonFiles\lib\python\debugpy\__main__.py", line 45, in <module>
    cli.main()
  File "c:\Users\houst\.vscode\extensions\ms-python.python-2021.10.1365161279\pythonFiles\lib\python\debugpy/..\debugpy\server\cli.py", line 444, in main
    run()
  File "c:\Users\houst\.vscode\extensions\ms-python.python-2021.10.1365161279\pythonFiles\lib\python\debugpy/..\debugpy\server\cli.py", line 285, in run_file
    runpy.run_path(target_as_str, run_name=compat.force_str("__main__"))
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.9_3.9.2032.0_x64__qbz5n2kfra8p0\lib\runpy.py", line 268, in run_path 
    return _run_module_code(code, init_globals, run_name,
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.9_3.9.2032.0_x64__qbz5n2kfra8p0\lib\runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.9_3.9.2032.0_x64__qbz5n2kfra8p0\lib\runpy.py", line 87, in _run_code 
    exec(code, run_globals)
  File "c:\Users\houst\API\Scraper.py", line 34, in <module>
    search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text
  File "C:\Users\houst\Envs\Mach\lib\site-packages\selenium\webdriver\remote\webelement.py", line 718, in find_element
    return self._execute(Command.FIND_CHILD_ELEMENT,
  File "C:\Users\houst\Envs\Mach\lib\site-packages\selenium\webdriver\remote\webelement.py", line 693, in _execute
    return self._parent.execute(command, params)
  File "C:\Users\houst\Envs\Mach\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 418, in execute
    self.error_handler.check_response(response)
  File "C:\Users\houst\Envs\Mach\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 243, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchElementException: Message: no such element: Unable to locate element: {"method":"xpath","selector":".//span[contains(@class,'sc-ministats-small')]/span"}

uj5u.com熱心網友回復：

最好只包含在try except塊中引發例外的最少行。

在您的回溯中：

File "c:\Users\houst\API\Scraper.py", line 34, in <module>
    search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text

您可以看到引發例外的確切行和編號。

稍后的：

selenium.common.exceptions.NoSuchElementException: Message: no such element: Unable to locate element: {"method":"xpath","selector":".//span[contains(@class,'sc-ministats-small')]/span"}

您會看到正在引發的確切例外。

for回圈具有用于繼續下一次迭代的內置機制。該continue宣告。

使用這些知識，您可以將違規行包裝在try/ 中except并僅捕獲您關心的例外。您還需要先匯入該例外。

from selenium.common.exceptions import NoSuchElementException
try:
    search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text
except NoSuchElementException:
    continue

您還可以修改你的for回圈來遍歷從1通過32使用range(1, 33)。這樣你就不需要手動 increment i。

完整代碼：

import time
from selenium import webdriver
import selenium
from selenium.webdriver.chrome import service
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import NoSuchElementException
import pandas as pd

#class scraperdata():

ser = Service("C:\Program Files (x86)\chromedriver.exe")
options = webdriver.ChromeOptions()
options.add_experimental_option('excludeSwitches', ['enable-logging'])
driver = webdriver.Chrome(options=options,service=ser)
driver.get('https://soundcloud.com/jujubucks')
print(driver.title)

wait = WebDriverWait(driver,30)

wait.until(EC.element_to_be_clickable((By.ID,"onetrust-accept-btn-handler"))).click()

for i in range(1, 33):
    song_contents = driver.find_element(By.XPATH, "//li[@class='soundList__item'][{}]".format(i))
    driver.execute_script("arguments[0].scrollIntoView(true);",song_contents)
    try:    
        search = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__username')]/span").text
        search_song = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__title')]/span").text
        search_date = song_contents.find_element(By.XPATH, ".//time[contains(@class,'relativeTime')]/span").text
        search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text
    except NoSuchElementException:
        continue
    if search_plays == False:
        continue
    
    option ={
        'Artist': search, 
        'Song_title': search_song, 
        'Date': search_date,
        'Streams': search_plays
    }
    song_list = []
    song_list.append(option)

    df = pd.DataFrame(song_list)
    print(df)
driver.quit()

uj5u.com熱心網友回復：

import time
from selenium import webdriver
import selenium
from selenium.webdriver.chrome import service
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import pandas as pd

#class scraperdata():

ser= Service("C:\Program Files (x86)\chromedriver.exe")
options = webdriver.ChromeOptions()
options.add_experimental_option('excludeSwitches', ['enable-logging'])
driver = webdriver.Chrome(options=options,service=ser)
driver.get('https://soundcloud.com/jujubucks')
print(driver.title)

wait = WebDriverWait(driver,30)

wait.until(EC.element_to_be_clickable((By.ID,"onetrust-accept-btn-handler"))).click()


    i = 1
    for _ in range(32):
        try:
           song_contents = driver.find_element(By.XPATH, "//li[@class='soundList__item'][{}]".format(i))
        driver.execute_script("arguments[0].scrollIntoView(true);",song_contents)
           search = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__username')]/span").text
           search_song = song_contents.find_element(By.XPATH, ".//a[contains(@class,'soundTitle__title')]/span").text
           search_date = song_contents.find_element(By.XPATH, ".//time[contains(@class,'relativeTime')]/span").text
           search_plays = song_contents.find_element(By.XPATH, ".//span[contains(@class,'sc-ministats-small')]/span").text
           i =1
           if search_plays == False:
              continue
        
           option ={
            'Artist': search, 
            'Song_title': search_song, 
            'Date': search_date,
            'Streams': search_plays
          }
          song_list = []
          song_list.append(option)

          df = pd.DataFrame(song_list)
          print(df)
       except Exception:
          pass
driver.quit()

在 for 回圈中使用 try 塊，進一步您可以將有傳遞例外趨勢的所需部分放入 try 塊中。希望這有幫助。

uj5u.com熱心網友回復：

for 回圈并不是為要跳過的專案而設計的。最好使用 while 回圈重寫它。

轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/342830.html

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