定制pattern的string模板(template) 详解
string.Template的pattern是一个正则表达式, 可以通过覆盖pattern属性, 定义新的正则表达式.
如: 使用新的定界符"{{", 把{{var}}作为变量语法.
代码:
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# -*- coding: utf-8 -*- ''''' Created on 2014.6.5 @author: Administrator @edition : python 3.3.0, eclipse pydev ''' import string t = string.Template( '$var' ) print (t.pattern.pattern) class MyTemplate(string.Template): delimiter = '{{' pattern = r ''''' \{\{(?: (?P<escaped>\{\{) | # Escape sequence of two delimiters (?P<named>[_a-z][_a-z0-9]*)\}\} | # delimiter and a Python identifier {(?P<braced>[_a-z][_a-z0-9]*)}\}\} | # delimiter and a braced identifier (?P<invalid>) # Other ill-formed delimiter exprs ) ''' t2 = MyTemplate( ''''' {{{{ {{var}} ''' ) print ( 'MATCHES: ' , t2.pattern.findall(t2.template)) print ( 'SUBSTITUTED: ' , t2.safe_substitute(var = 'replacement' )) |
输出:
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\$(?: (?P<escaped>\$) | # Escape sequence of two delimiters (?P<named>[_a - z][_a - z0 - 9 ] * ) | # delimiter and a Python identifier {(?P<braced>[_a - z][_a - z0 - 9 ] * )} | # delimiter and a braced identifier (?P<invalid>) # Other ill-formed delimiter exprs ) MATCHES: [( '{{' , ' ', ' ', ' '), (' ', ' var ', ' ', ' ')] SUBSTITUTED: {{ replacement |
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原文链接:http://blog.csdn.net/caroline_wendy/article/details/28625179