Python 使用计数器后循环没有中断

Question

我在下面的代码末尾添加了一个计数器。但是，当代码继续运行超过计数器 10 时，我将其设置为中断。不知道我做错了什么。

chromedriver='C:\Users\user\Downloads\chromedriver_win32\chromedriver.exe'

options=webdriver.ChromeOptions()
options.add_argument('headless')
options.add_argument('window-size=1200x600')
browser=webdriver.Chrome(executable_path=chromedriver,chrome_options=options)

path='C:/Users/something.xlsx'

xls=pd.read_excel(path)
data=xls["companyname"].tolist()
data=[w.replace('" "','+') for w in data]

book=openpyxl.load_workbook(path)
sheet=book.active
try:
    delete=book['Python Data']
    book.remove(delete)
except Exception:
    pass
book.create_sheet('Python Data')
ws1=book['Python Data']
book.save(path)

counter=0

while data:
    for item in data:
        browser.get('https://duckduckgo.com/?q='+item+'&t=h_')
        results = browser.find_elements_by_id('links')
        num_page_items = len(results)
        for i in range(num_page_items):
            mylist = results[i].text
            row=len(ws1['A']) + 1
            ws1.cell(row=1,column=1,value="Results")
            ws1.cell(row=row,column=1,value=mylist)
            book.save(path)
            counter += 1
            print(counter)
            if counter==10:
                break

Answer 1

您的代码在到达 counter == 10 后再次执行，因为无限 while data 语句。请注意，break 不会在此处转义 while 语句，它会转义 for i in range(num_page_items).

请使用以下代码：

# notice lack of while data statement
for item in data:
    browser.get('https://duckduckgo.com/?q='+item+'&t=h_')
    results = browser.find_elements_by_id('links')
    num_page_items = len(results)
    for i in range(num_page_items):
        mylist = results[i].text
        row=len(ws1['A']) + 1
        ws1.cell(row=1,column=1,value="Results")
        ws1.cell(row=row,column=1,value=mylist)
        book.save(path)
        counter += 1
        print(counter)
        if counter==10:
            break

Answer 2

如4.4. break and continue Statements, and else Clauses on Loops中所写：

The break statement, like in C, breaks out of the innermost enclosing for or while loop.

在您的代码中是：

for i in range(num_page_items):
     .....

Python 使用计数器后循环没有中断

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