s.headers.update({'user-agent': 'Mozilla/5.0'})中的update是什么
时间: 2024-01-18 08:03:31 浏览: 142
update是一个方法,可以用来更新字典s的键值对。在这里,它被用来更新请求头中的User-Agent键对应的值。具体地,它将键值对{'user-agent': 'Mozilla/5.0'}添加到s的请求头中。如果请求头中已经存在'user-agent'键,则它的值将被覆盖为'Mozilla/5.0'。
相关问题
import requestsfrom bs4 import BeautifulSoupimport pandas as pd# 构造请求头headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'}# 发送请求response = requests.get('https://book.douban.com/tag/', headers=headers)# 解析页面soup = BeautifulSoup(response.text, 'html.parser')# 获取标签列表tag_list = soup.find_all('a', class_='tag-title-wrapper')book_list = []for tag in tag_list: # 构造标签页的链接 tag_url = tag['href'] # 发送标签页的请求 tag_response = requests.get(tag_url, headers=headers) # 解析标签页 tag_soup = BeautifulSoup(tag_response.text, 'html.parser') # 获取图书列表 book_items = tag_soup.find_all('li', class_='subject-item') # 遍历图书列表,获取图书名称和作者 for item in book_items: title = item.find('div', class_='info').h2.a.text.strip() author = item.find('div', class_='info').find('div', class_='pub').text.strip().split('/')[0] book_list.append((title, author))# 将图书列表转换为 DataFramedf = pd.DataFrame(book_list, columns=['书名', '作者'])# 导出为 Excel 文件df.to_excel('book_list.xlsx', index=False)改进这段代码
这段代码可以改进的地方有:
1. 使用 requests 库发送 HTTP 请求时,建议使用 Session 来管理请求,可以提高请求的效率,并且在发送多个请求时可以维持会话状态;
2. 使用 BeautifulSoup 解析 HTML 页面时,可以指定解析器,例如使用 lxml 解析器可以提高解析效率;
3. 在获取图书名称和作者时,可以使用 CSS 选择器来提取信息,例如使用 .info h2 a 来选择书名元素,使用 .info .pub 来选择作者元素;
4. 将代码封装成一个函数,提高代码的可重用性。
改进后的代码如下:
```
import requests
from bs4 import BeautifulSoup
import pandas as pd
# 构造请求头
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'
}
# 创建 Session 对象
session = requests.Session()
session.headers.update(headers)
def get_book_list():
# 发送请求
response = session.get('https://book.douban.com/tag/')
# 解析页面
soup = BeautifulSoup(response.text, 'lxml')
# 获取标签列表
tag_list = soup.select('.tag-title-wrapper a')
book_list = []
for tag in tag_list:
# 构造标签页的链接
tag_url = tag['href']
# 发送标签页的请求
tag_response = session.get(tag_url)
# 解析标签页
tag_soup = BeautifulSoup(tag_response.text, 'lxml')
# 获取图书列表
book_items = tag_soup.select('.subject-item')
# 遍历图书列表,获取图书名称和作者
for item in book_items:
title = item.select_one('.info h2 a').text.strip()
author = item.select_one('.info .pub').text.strip().split('/')[0]
book_list.append((title, author))
# 将图书列表转换为 DataFrame
df = pd.DataFrame(book_list, columns=['书名', '作者'])
# 导出为 Excel 文件
df.to_excel('book_list.xlsx', index=False)
if __name__ == '__main__':
get_book_list()
```
import re,tkinter,requests,threading,tqdm as tt root = tkinter.Tk() root.title('在线视频解析') root.geometry('500x590+550+350') headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0'} ac = tkinter.Listbox(root, width=50, height=20, font=('黑体', 12)) ac.grid(row=2, columnspan=10, sticky="n" + "s" + "w" + "e") def sousuo(): i = b1.get() ac.delete(0, 'end') def extract_music_info(content): p = '<em>|</em>' content = re.sub(p, '', content, flags=re.S) pattern = re.compile('subject.*?href="(.*?)">(.*?)</a>', flags=re.S) return pattern.findall(content) def search_music(): url = 'https://www.hifini.com/search-' + i + '-1.htm' response = requests.get(url=url, headers=headers) return response.text def update_listbox(music_list): for music in music_list: pppp = music[1] + ":" + music[0] ac.insert('end', pppp) content = search_music() music_list = extract_music_info(content) update_listbox(music_list) def xiazzi(): def download_music(): ppp = ac.get(ac.curselection()) pp = re.search('thread.*?htm', ppp) v = pp.group() url1 = 'https://www.hifini.com/' + v response = requests.get(url=url1, headers=headers) ppp = response.text l2 = re.search('<script>.*?title:..(.*?).,.*?author:.(.*?).,.*?url:..(.*?).,', ppp, flags=re.S) p = 'https://www.hifini.com/' + l2.group(3) response = requests.get(url=p, headers=headers, stream=True) # 设置 stream=True 以启用流式下载 total_size = int(response.headers.get('Content-Length')) music_name = '{}-{}.mp3'.format(l2.group(2), l2.group(1)) progress_bar = tt.tqdm(total=total_size, unit='B', unit_scale=True) # 创建进度条 with open(music_name, 'wb') as f: for data in response.iter_content(chunk_size=1024): progress_bar.update(len(data)) # 更新进度条 f.write(data) progress_bar.close() # 关闭进度条 print(music_name) threading.Thread(target=download_music).start() a1 = tkinter.Label(root, text='音乐下载器', anchor="center", font=('黑体', 24)) a1.grid(row=0, columnspan=10, sticky="n" + "s" + "w" + "e") b1 = tkinter.Entry(root, width=35, font=('黑体', 16), ) b1.grid(row=1, column=3, padx=15) search_button = tkinter.Button(root, text='搜索', command=sousuo) search_button.grid(row=1, column=4) download_button = tkinter.Button(root, text='下载', command=xiazzi) download_button.grid(row=3, column=4) root.mainloop() 将download_button带有下载行为的按钮添加进列表,
您可以直接将download_button添加到ac(Listbox)中,然后在xiazzi函数中获取所选项,并执行下载操作。以下是修改后的代码示例:
```python
import re
import tkinter
import requests
import threading
import tqdm as tt
root = tkinter.Tk()
root.title('在线视频解析')
root.geometry('500x590+550+350')
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0'}
ac = tkinter.Listbox(root, width=50, height=20, font=('黑体', 12))
ac.grid(row=2, columnspan=10, sticky="n" + "s" + "w" + "e")
def sousuo():
i = b1.get()
ac.delete(0, 'end')
def extract_music_info(content):
p = '<em>|</em>'
content = re.sub(p, '', content, flags=re.S)
pattern = re.compile('subject.*?href="(.*?)">(.*?)</a>', flags=re.S)
return pattern.findall(content)
def search_music():
url = 'https://www.hifini.com/search-' + i + '-1.htm'
response = requests.get(url=url, headers=headers)
return response.text
def update_listbox(music_list):
for music in music_list:
pppp = music[1] + ":" + music[0]
ac.insert('end', pppp)
content = search_music()
music_list = extract_music_info(content)
update_listbox(music_list)
def xiazzi():
def download_music():
ppp = ac.get(ac.curselection())
pp = re.search('thread.*?htm', ppp)
v = pp.group()
url1 = 'https://www.hifini.com/' + v
response = requests.get(url=url1, headers=headers)
ppp = response.text
l2 = re.search('<script>.*?title:..(.*?).,.*?author:.(.*?).,.*?url:..(.*?).,', ppp, flags=re.S)
p = 'https://www.hifini.com/' + l2.group(3)
response = requests.get(url=p, headers=headers, stream=True)
total_size = int(response.headers.get('Content-Length'))
music_name = '{}-{}.mp3'.format(l2.group(2), l2.group(1))
progress_bar = tt.tqdm(total=total_size, unit='B', unit_scale=True)
with open(music_name, 'wb') as f:
for data in response.iter_content(chunk_size=1024):
progress_bar.update(len(data))
f.write(data)
progress_bar.close()
print(music_name)
ac_value = ac.get(ac.curselection())
download_button = tkinter.Button(ac, text=ac_value, command=xiazzi)
ac.insert('end', download_button)
a1 = tkinter.Label(root, text='音乐下载器', anchor="center", font=('黑体', 24))
a1.grid(row=0, columnspan=10, sticky="n" + "s" + "w" + "e")
b1 = tkinter.Entry(root, width=35, font=('黑体', 16), )
b1.grid(row=1, column=3, padx=15)
search_button = tkinter.Button(root, text='搜索', command=sousuo)
search_button.grid(row=1, column=4)
root.mainloop()
```
这样,当用户选择某个音乐后,下载按钮会根据选择的音乐动态更新,点击下载按钮即可执行下载操作。
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