Python实现的简单模板引擎功能示例

#coding:utf- 8
__author__="sdm"
__author_email='sdmzhu3@gmail.com'
__date__ ="$2009-8-25 21:04:13$"
'' '
pytpl 类似 php的模板类
'' '
import sys
import StringIO
import os.path
import os
#模 板的缓存
_tpl_cache={}
class Pytpl:
  def __init__(self,tpl_path='./' ):
    self.tpl_path=tpl_path
    self.data={}
    self.output = StringIO.StringIO()
    pass
  def set(self,name,value):
    '' '
    设 置模板变量
    '' '
    self.data[name]=value;
    pass
  def get(self,name):
    '' '
    得 到模板变量
    '' '
    t={}
    return t.get(name, '' )
    pass
  def tpl(self,tplname):
    '' '
    渲 染模板
    '' '
    f=self.tpl_path+tplname
    if not os.path.exists(f):
      raise Exception('tpl:[%s] is not exists' % f)
    mtime=os.stat(f).st_mtime
    if  not _tpl_cache.has_key(f) or _tpl_cache[f][ 'time' ]<mtime:
      src_code=self.__compile__(open(f).read())
      try :
        t=open(f+'.py' , 'w' )
        t.write(src_code)
        t.close()
      except:
        pass
      py_code=compile(src_code, f+'.py' , 'exec' )
      _tpl_cache[f]={'code' :py_code, 'time' :mtime}
    else :
      py_code= _tpl_cache[f]['code' ]
    exec(py_code, {'self' :self}, self.data)
    return self.output.getvalue()
  def execute(self,code,data,tplname):
    '' '
    执 行这个模板
    '' '
    py_file_name=tplname+'.py'
    f=open(py_file_name,'w' )
    f.write(code)
    f.close()
    execfile(py_file_name, {'self' :self}, data)
  def __compile__ (self,code):
    '' '
    编 译模板
    查找 <"/n" )
      t=[]
      for i in lines:
        indent2=indent
        tmp=i.strip("  /n/r" )
        c=tmp[len(tmp)-1 :len(tmp)]
        # 判定最后一个字符
        if (c== '{' ):
          indent+=1
          tmp=tmp[0 :len(tmp)- 1 ]+ ":"
        elif(c=='}' ):
          indent-=1
          tmp=tmp[0 :len(tmp)- 1 ]
        t.append((' ' * 4 *indent2) +tmp )
      return  "/n" .join(t)
    while  1 :
      if i>=tlen: break
      c=code[i];
      if status== 0 :
        # 编译加速
        pos_start=code.find(flag_start,pos_end);
        if (pos_start>- 1 ):
          s=code[pos_end:pos_start]
          t_code= 'echo ( ' +repr(s)+ ')'
          t_code=' ' *indent* 4 +t_code
          if s:
            py_code.append(t_code)
          i=pos_start
          last_pos=i
          # 进入代码状态
          status=1
          continue
        else :
          # 没有没有找到
          pos_start=tlen
          t_code='echo ( ' +repr(code[pos_end:pos_start])+ ' ) '
          t_code=' ' *indent* 4 +t_code
          py_code.append(t_code)
          break
      if status== 1 :
        # 查找结束标记
        pos_end=code.find(flag_end,i)
        if (pos_end>- 1 ):
          # 需要跳过<"#coding:utf-8/nimport sys;global echo;echo=self.output.write/n"
    py_code_str+="/n" .join(py_code)
    py_code_str=py_code_str.replace("/t" , "  " )
    return py_code_str
def test():
  tpl=Pytpl('./' );
  tpl.set('title' , '标题3' )
  print tpl.tpl('test.html' )
  pass
if __name__ == "__main__" :
  test()