bs4之標籤樹的平行遍歷

# 平行遍歷的內容不一定是標籤，還可能是string
import requests
from bs4 import BeautifulSoup
url = "https://python123.io/ws/demo.html"
r = requests.get(url, timeout=30)
r.encoding = r.apparent_encoding
demo = r.text
soup = BeautifulSoup(demo, "html.parser")
# 上一個平行節點
print("上："+soup.a.previous_sibling) # a標籤的上一個平行節點不一定是標籤，可能是p標籤的內容
print(soup.a.previous_sibling.previous_sibling) #上上一個平行節點，可能爲空值
# 下一個平行節點
print("下"+soup.a.next_sibling)
print(soup.a.next_sibling.next_sibling)
# 遍歷平行節點，迭代類型，只能用在for循環之中
print("之前")
for sibling in soup.a.previous_siblings: # 遍歷a標籤前面的平行節點
    print(sibling)
print("之後")
for sibling in soup.a.next_siblings: # 遍歷a標籤後面的平行節點
    print(sibling)