[英]Python - For Loop if statement skip to next iteration in Selenium
我正在使用硒來遍歷變量參數的不同組合,並從網站下載數據。 但是,當沒有數據時,for循環功能將停止工作。 我還注意到,硒停止運行時,網頁上會包含一個標記為“無法產生結果”的文本。 因此,我想使用帶有硒的if
語句來搜索“無法產生結果”,如果找到了上述文本,則跳到下一個循環。 一個例子是這樣的:
import os
from selenium import webdriver
import zipfile
import pandas as pd
import time
for i in to_loop:
# directories
link = 'http://www.gaez.iiasa.ac.at/w/ctrl?
_flow=Vwr&_view=Welcome&idAS=0&idFS=0&fieldmain=main_&idPS=0'
## Access Chrome Driver to use selenium
# Define Download Directory
chrome_options = webdriver.ChromeOptions()
prefs = {'download.default_directory': 'C:/.../Download'}
chrome_options.add_experimental_option('prefs', prefs)
driver = webdriver.Chrome(
executable_path='C:/.../chromedriver.exe',
chrome_options=chrome_options)
driver.get(link)
# Enter username and password
driver.find_element_by_name('_username').send_keys(username)
driver.find_element_by_name('_password').send_keys(password)
driver.find_element_by_id('buttonSubmit__login').click()
# Click on Suitability and Potential Yield link
driver.find_element_by_name('_targetfieldmain=main_py&_...').click()
# Click on Agro-ecological suitability and productivity link
driver.find_element_by_name('&fieldmain=main_py&idPS=0&...').click()
# Click on Agro-ecological suitability and productivity list
driver.find_element_by_css_selector('input[value="
{}"]'.format(i[0])).click()
# Click on crop link
driver.find_element_by_css_selector("input.linksubmit[value=\"▸
Crop\"]").click()
AES_and_P = i[0]
driver.find_element_by_css_selector('input[value="
{}"]'.format(i[1])).click()
# Click on Water Supply Link
driver.find_element_by_css_selector("input.linksubmit[value=\"▸ Water
Supply\"]").click()
Crop = i[1]
driver.find_element_by_css_selector('input[value="
{}"]'.format(i[2])).click()
# Click on Input Level Link
driver.find_element_by_css_selector("input.linksubmit[value=\"▸ Input
Level\"]").click()
Water_Supply = i[2]
driver.find_element_by_css_selector('input[value="
{}"]'.format(i[3])).click()
Input_Level = i[3]
# If statement to skip to next loop if text found
data_check = driver.find_elements_by_partial_link_text('Cannot produce
results.')
if data_check[0].is_displayed():
continue
# Click on Time Period and Select Baseline
driver.find_element_by_css_selector("input.linksubmit[value=\"▸ Time
Period\"]").click()
driver.find_element_by_css_selector("input.linksubmit[value=\"1961-
1990\"]").click()
# Click on Geographic Areas Link
driver.find_element_by_css_selector("input.linksubmit[value=\"▸
Geographic Areas\"]").click()
# Unselect all countries
driver.find_element_by_xpath('//*[@id="fieldareaList__pln-1"]').click()
# Close tab for Northern Africa
driver.find_element_by_xpath('//*[@id="rg1-66-Northern
Africa"]/span').click()
# Wait 1 second
time.sleep(1)
# Click geographic area then country
driver.find_element_by_xpath('//label[text()="{}"]/following-
sibling::span'.format(geographic_area)).click()
driver.find_element_by_xpath('//label[text()="
{}"]'.format(country)).click()
# Click on Map Link
driver.find_element_by_css_selector("input.linksubmit[value=\"▸
Map\"]").click()
# Download Data
driver.find_element_by_xpath('//*[@id="buttons"]/a[4]/img').click()
# Wait 2 seconds
time.sleep(2)
# Download blah blah
path = 'C:/.../Download'
destination_folder = 'C:/.../CSV_Files'
file_list = [os.path.join(path, f) for f in os.listdir(path)]
time_sorted_list = sorted(file_list, key=os.path.getmtime)
file_name = time_sorted_list[-1]
# decompress the zipped file here
myzip = zipfile.ZipFile(file_name)
# Wait 1 second
time.sleep(1)
myzip.extract('data.asc', destination_folder)
# Save data.asc file as .csv and rename reflects download selections
newfilename = country + Crop + Water_Supply + Input_Level + AES_and_P
df = pd.read_table(os.path.join(destination_folder, 'data.asc'),
sep="\s+", skiprows=6, header=None)
df.to_csv(os.path.join(destination_folder, '{}.csv'.format(newfilename)))
# Delete downloaded data.asc file
delete_data_file = "C:/.../CSV_Files/data.asc"
# if file exists, delete it
if os.path.isfile(delete_data_file):
os.remove(delete_data_file)
else: # Show error
print("Error: %s file not found" % delete_data_file)
driver.close()
但是,此代碼只是在繼續時停止了該函數,沒有完成代碼的下載部分,而是遍歷了循環的其余部分。 有什么解決的辦法嗎? 另外,請讓我知道問題是否令人困惑。
經過評論中的討論,我相信至少可以看到您的問題的一部分。 python continue
關鍵字並不表示“繼續執行其余的控制流”,而是表示“繼續執行循環的下一個迭代,之后跳過所有內容”。
例如,在下面的Python代碼中:
a = []
for i in range(10):
if i == 5:
continue
a.append(i)
print(a)
結果將是:
[0, 1, 2, 3, 4, 6, 7, 8, 9]
而不是,使用您以前的邏輯
[5]
因此,要使代碼繼續運行,您需要翻轉邏輯,以便在條件不成立時跳過,例如:
if not data_check[0].is_displayed():
continue
盡管我個人從未遇到過與您犯過相同錯誤的人,但是我確實強調,從語義上講,“繼續”是指繼續執行該程序的下一部分,這似乎更有意義。 在continue
Python的選擇很大程度上來自歷史上對continue
作為關鍵字的用法, 尤其是在C語言中 。 在這種情況下,我們可以看到continue
為更多的擴展的break
聲明為“跳過”。
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