python之找不到别名的词法分析器

我正在尝试使用 Pygments 和 Beautiful Soup 作为我为 Google App Engine 构建的博客软件的代码突出显示解决方案。

它的工作原理是我的 HTML 帖子将使用预标记来标识代码。像这样:

<p>Check out this cool code example<p>     
<pre class="python"> 
        import this 
        def demo(): 
            pass</pre> 

BeautifulSoup 捕获 pre 标签之间的部分并将其传递给 Pygments。 Pygments 假设检查类值并应用正确的 lexar。然后 Pygments 应用格式并用格式化文本替换原始文本。该解决方案在 SaltyCrane's Blog 中有更详细的解释。 .

错误

ClassNotFound: no lexer for alias [u'python'] found 

也许我只是没有正确导入模块？

代码

from google.appengine.ext import db 
import fix_path 
import bs4 
import pygments 
from bs4 import BeautifulSoup 
from pygments import highlight 
from pygments.lexers import get_lexer_by_name 
from pygments.formatters import HtmlFormatter 
 
 
    def formatter(p): 
        soup = BeautifulSoup(p.otext) 
        preblocks = soup.findAll('pre') 
        for pre in preblocks: 
            if pre.has_key('class'): 
                code = ''.join([unicode(item) for item in pre.contents]) 
                code = unescape_html(code) 
                lexer = lexers.get_lexer_by_name(pre['class']) 
                formatter = formatters.HtmlFormatter() 
                code_hl = highlight(code, lexer, formatter) 
                pre.replaceWith(BeautifulSoup(code_hl)) 
            else: 
                print "No Go" 
        return unicode(soup) 

回溯

Traceback (most recent call last): 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 1536, in __call__ 
    rv = self.handle_exception(request, response, e) 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 1530, in __call__ 
    rv = self.router.dispatch(request, response) 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 1278, in default_dispatcher 
    return route.handler_adapter(request, response) 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 1102, in __call__ 
    return handler.dispatch() 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 572, in dispatch 
    return self.handle_exception(e, self.app.debug) 
  File "C:\Users\john\webdev\google\lib\webapp2\webapp2.py", line 570, in dispatch 
    return method(*args, **kwargs) 
  File "C:\Users\john\webdev\workspace\bsby\views.py", line 45, in post 
    p.ftext = utils.formatter(p) 
  File "C:\Users\john\webdev\workspace\bsby\utils.py", line 18, in formatter 
    lexer = lexers.get_lexer_by_name(pre['class']) 
  File "C:\Users\john\webdev\workspace\bsby\lib\pygments\lexers\__init__.py", line 80, in get_lexer_by_name 
    raise ClassNotFound('no lexer for alias %r found' % _alias) 
ClassNotFound: no lexer for alias [u'python'] found 

请您参考如下方法:

是的，这就是问题所在。我没有导入脚本运行所需的库。这是正确的代码。

import fix_path 
import bs4 
import pygments 
from bs4 import BeautifulSoup 
from pygments import highlight 
from pygments import lexers 
from pygments import formatters 
 
 
    def formatter(p): 
        soup = BeautifulSoup(p.otext) 
        preblocks = soup.findAll('pre') 
        for pre in preblocks: 
            if pre.has_key('class'): 
                code = ''.join([unicode(item) for item in pre.contents]) 
                lexer = lexers.get_lexer_by_name("python") 
                formatter = formatters.HtmlFormatter() 
                code_hl = highlight(code, lexer, formatter) 
                pre.replaceWith(BeautifulSoup(code_hl)) 
                return unicode(soup) 
            else: 
                return null 

这是另一个问题....

我想像这样动态拉取 lexar 名称...

lexer = lexers.get_lexer_by_name(pre['class']) 

但是，当我这样做时，出现以下错误。

ClassNotFound: no lexer for alias [u'python'] found 

如果我这样做

lexer = lexers.get_lexer_by_name("python") 

它有效，但仅适用于 python。