爬虫下载图片

使用爬虫下载图片

刚学习爬虫没几天，希望大佬们多多提意见！
我爬的是某贴吧，url大家自行设置吧。

import requests
from lxml import etree

"""
获取详情页的url
获取图片url,下载保存
构造下一页详情页url
循坏
"""

def url_names(n):
    #构建详情页的url地址
    url_name = "https://tieba.baidu.com"+str(n)
    return url_name

def next_url(next_url_if,n):
    # 下一页的url
    if "下一页" in next_url_if:
        n += 1
    else:
        n = "end"
    return n

def img_url_name(url_name,list):
    htmls = requests.get(url_name,)
    url_htmls = htmls.text
    html = etree.HTML(url_htmls)
    img_path = html.xpath("//div//img[@class='BDE_Image']/@src")
    for i in img_path:
        list.append(i)
    next_if_else = html.xpath("//li[@class='l_pager pager_theme_4 pb_list_pager']/a[@href]/text()")
    return next_if_else,list


def downloader(img_path):
    for name,img_data_url in enumerate(img_path):
        name = str(name)
        req = requests.get(img_data_url)
        with open(name+".jpg","wb") as f:
            f.write(req.content)
            print("保存成功")

def main():
    n = 1
    list = []
    while n != "end":
        url_name = url_names(n)
        next_url_if,list = img_url_name(url_name,list)
        n = next_url(next_url_if,n)

    downloader(list)
    print("下载完成!")

if __name__ == "__main__":
    main()