安装lxml

首先需要pip install lxml安装lxml库。

如果你在ubuntu上遇到了以下错误:

#include "libxml/xmlversion.h"
compilation terminated.
error: command 'x86_-linux-gnu-gcc' failed with exit status 1
----------------------------------------
Cleaning up...
 Removing temporary dir /tmp/pip_build_root...
Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_root/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('
', '
'), __file__, 'exec'))" install --record /tmp/pip-O4cIn6-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip_build_root/lxml
Exception information:
Traceback (most recent call last):
 File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
 status = self.run(options, args)
 File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 283, in run
 requirement_set.install(install_options, global_options, root=options.root_path)
 File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1435, in install
 requirement.install(install_options, global_options, *args, **kwargs)
 File "/usr/lib/python2.7/dist-packages/pip/req.py", line 706, in install
 cwd=self.source_dir, filter_stdout=self._filter_install, show_stdout=False)
 File "/usr/lib/python2.7/dist-packages/pip/util.py", line 697, in call_subprocess
 % (command_desc, proc.returncode, cwd))
InstallationError: Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_root/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('
', '
'), __file__, 'exec'))" install --record /tmp/pip-O4cIn6-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip_build_root/lxml

请安装以下依赖：

sudo apt-get install libxml2-dev libxslt1-dev

Python代码

下面是生成sitemap和sitemapindex索引的代码，可以按照需求传入需要的参数，或者增加字段：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import io
import re
from lxml import etree
def generate_xml(filename, url_list):
 """Generate a new xml file use url_list"""
 root = etree.Element('urlset',
 xmlns="http://www.sitemaps.org/schemas/sitemap/0.9")
 for each in url_list:
 url = etree.Element('url')
 loc = etree.Element('loc')
 loc.text = each
 url.append(loc)
 root.append(url)
 header = u'<?xml version="1.0" encoding="UTF-8"?>
'
 s = etree.tostring(root, encoding='utf-8', pretty_print=True)
 with io.open(filename, 'w', encoding='utf-8') as f:
 f.write(unicode(header+s))
def update_xml(filename, url_list):
 """Add new url_list to origin xml file."""
 f = open(filename, 'r')
 lines = [i.strip() for i in f.readlines()]
 f.close()
 old_url_list = []
 for each_line in lines:
 d = re.findall('<loc>(http://.+)</loc>', each_line)
 old_url_list += d
 url_list += old_url_list
 generate_xml(filename, url_list)
def generatr_xml_index(filename, sitemap_list, lastmod_list):
 """Generate sitemap index xml file."""
 root = etree.Element('sitemapindex',
 xmlns="http://www.sitemaps.org/schemas/sitemap/0.9")
 for each_sitemap, each_lastmod in zip(sitemap_list, lastmod_list):
 sitemap = etree.Element('sitemap')
 loc = etree.Element('loc')
 loc.text = each_sitemap
 lastmod = etree.Element('lastmod')
 lastmod.text = each_lastmod
 sitemap.append(loc)
 sitemap.append(lastmod)
 root.append(sitemap)
 header = u'<?xml version="1.0" encoding="UTF-8"?>
'
 s = etree.tostring(root, encoding='utf-8', pretty_print=True)
 with io.open(filename, 'w', encoding='utf-8') as f:
 f.write(unicode(header+s))
if __name__ == '__main__':
 urls = ['http://www.baidu.com'] * 10
 mods = ['2004-10-01T18:23:17+00:00'] * 10
 generatr_xml_index('index.xml', urls, mods)

效果

生成的效果应该是这种格式：

sitemap格式:

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
 <url>
 <loc>http://www.example.com/foo.html</loc>
 </url>
</urlset>
sitemapindex格式：
<?xml version="1.0" encoding="UTF-8"?>
 <sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
 <sitemap>
 <loc>http://www.example.com/sitemap1.xml.gz</loc>
 <lastmod>2004-10-01T18:23:17+00:00</lastmod>
 </sitemap>
 <sitemap>
 <loc>http://www.example.com/sitemap2.xml.gz</loc>
 <lastmod>2005-01-01</lastmod>
 </sitemap>
 </sitemapindex>

lastmod时间格式的问题

格式是用ISO 8601的标准，如果是linux/unix系统，可以使用以下函数获取

def get_lastmod_time(filename):
 time_stamp = os.path.getmtime(filename)
 t = time.localtime(time_stamp)
 # return time.strftime('%Y-%m-%dT%H:%M:%S+08:00', t)
 return time.strftime('%Y-%m-%dT%H:%M:%SZ', t)

优化

一般来说，用lxml效率低并且内存占用比较大，可以直接用文件的write方法创建。

def generate_xml(filename, url_list):
 with gzip.open(filename,"w") as f:
 f.write("""<?xml version="1.0" encoding="utf-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
""")
 for i in url_list:
 f.write("""<url><loc>%s</loc></url>
"""%i)
 f.write("""</urlset>""")
def append_xml(filename, url_list):
 with gzip.open(filename, 'r') as f:
 for each_line in f:
 d = re.findall('<loc>(http://.+)</loc>', each_line)
 url_list.extend(d)
 generate_xml(filename, set(url_list))
def modify_time(filename):
 time_stamp = os.path.getmtime(filename)
 t = time.localtime(time_stamp)
 return time.strftime('%Y-%m-%dT%H:%M:%S:%SZ', t)
def new_xml(filename, url_list):
 generate_xml(filename, url_list)
 root = dirname(filename)
 with open(join(dirname(root), "sitemap.xml"),"w") as f:
 f.write('<?xml version="1.0" encoding="utf-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
')
 for i in glob.glob(join(root,"*.xml.gz")):
 lastmod = modify_time(i)
 i = i[len(CONFIG.SITEMAP_PATH):]
 f.write("<sitemap>
<loc>http:/%s</loc>
"%i)
 f.write("<lastmod>%s</lastmod>
</sitemap>
"%lastmod)
 f.write('</sitemapindex>')