Question

n=0
def fetch_title():
  from bs4 import BeautifulSoup
  reqs = requests.get(URL).text
  soup = BeautifulSoup(reqs,"html5lib")
  for tag in soup.find_all("meta"):
      if tag.get("property", None) == "nv:news:title":
          title= tag.get("content", None)
          n=n+1          
          main_title = (n + ". " + title)
          return(title)
title1=fetch_title()
os.rename('NAVER_DONLOAD', title1)

到目前为止，我已经尝试了一下，但无济于事，我遇到了2个错误，我将传递txt文件中的url列表，它将解析链接中的数据并将数据保存在特定的文件夹。但我无法重命名该文件夹。

UnboundLocalError                         Traceback (most recent call last)
<ipython-input-7-2521214d94f6> in <module>()
     71           main_title = (n + ". " + title)
     72           return(title)
---> 73 title1=fetch_title()
     74 os.rename('NAVER_DONLOAD', title1)

<ipython-input-7-2521214d94f6> in fetch_title()
     68       if tag.get("property", None) == "nv:news:title":
     69           title= tag.get("content", None)
---> 70           n=n+1
     71           main_title = (n + ". " + title)
     72           return(title)

UnboundLocalError: local variable 'n' referenced before assignment

Answer 1

您需要使用global表示法才能使用在函数n之外定义的全局变量fetch_title()：

n=0

def fetch_title():
  from bs4 import BeautifulSoup
  reqs = requests.get(URL).text
  soup = BeautifulSoup(reqs,"html5lib")

  # Use global instance of n
  global n

  for tag in soup.find_all("meta"):
      if tag.get("property", None) == "nv:news:title":
          title= tag.get("content", None)
          n=n+1          
          main_title = (n + ". " + title)
          return(title)
title1=fetch_title()
os.rename('NAVER_DONLOAD', title1)

Answer 2

一个简单的全局n与.join一起解决了这个问题

这是更新的代码

def fetch_title():
  from bs4 import BeautifulSoup
  reqs = requests.get(URL).text
  soup = BeautifulSoup(reqs,"html5lib")
  for tag in soup.find_all("meta"):
      n=0
      if tag.get("property", None) == "nv:news:title":
          title= tag.get("content", None) 
          n+=1          
          main_title = '. '.join([str(n),title])
          return(main_title)
title1=fetch_title()
os.rename('NAVER_DONLOAD', title1)

如何使用os.rename以不增加的增量重命名文件夹

2 个答案: