使用lxml在Python中下载图片

Question

我需要在类似于以下HTML代码中找到一张图片：

...
<a href="/example/1"> 
    <img id="img" src="http://example.net/example.jpg" alt="Example" />
</a>
...

我正在使用lxml和requests。

以下是代码：

import lxml
from lxml import html
import requests

url = 'http://www.example.com'

r = requests.get(url)
tree = lxml.html.fromstring(r.content)

img = tree.get_element_by_id("img")
f = open("image.jpg",'wb')
f.write(requests.get(img['src']).content)

但是我遇到了一个错误：

Traceback (most recent call last):
  File "/Users/Name/Documents/Python/Example/Script.py", line 13, in <module>
    s = requests.get(img['src'])
  File "/Library/Python/2.6/site-packages/lxml/lxml.etree.pyx", line 1052, in lxml.etree._Element.__getitem__ (src/lxml/lxml.etree.c:38272)
TypeError: 'str' object cannot be interpreted as an index

有建议吗？

- Jiloc

---

建议：阅读文档并修复HTML。 - dav1d

Answer 1

尝试使用f.write(requests.get(img.attrib['src']).content)代码来获取图像并将其写入文件。

- asciimoo

Answer 2

import lxml.html
import requests

url = 'http://www.example.com/'
tree = lxml.html.parse(url)
img = tree.get_element_by_id('img')
img_url = img.attrib['src']

with open('image.jpg', 'wb') as outf:
    data = requests.get(img_url).content
    outf.write(data)

- Hugh Bothwell

---

img = tree.get_element_by_id('img')这一行不起作用，出现以下错误：Traceback (most recent call last): File "/Users/Example/Documents/Python/Example/Script.py", line 6, in <module> img = tree.get_element_by_id('img') AttributeError: 'lxml.etree._ElementTree' object has no attribute 'get_element_by_id'我尝试将tree = lxml.html.parse(url)替换为 tree = lxml.html.fromstring(requests.get(url).content)现在它可以工作了，感谢您的帮助！ - Jiloc