python:python基础教程实验1 文本标记

12年前

util.py:
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def lines(file):
    for line in file:
        yield line
        yield '\n'

def blocks(file):
    block = []
    for line in lines(file):
        if line.strip():
            block.append(line)
        elif block:
            yield ''.join(block).strip()
            block = []
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handler.py:
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class Handler:
    def callback(self, prefix, name, *args):
        method = getattr(self, prefix+name, None)
        if callable(method): return method(*args)

    def start(self, name):
        self.callback('start_',name)
    def end(self,name):
        self.callback('end_',name)
    def sub(self,name):
        def substitution(match):
            result = self.callback('sub_',name,match)
            if result is None: match.group(0)
            return result
        return substitution
class HTMLRenderer(Handler):
    def start_document(self):
        print '<html><head><title>...</title></head><body>'
    def end_document(self):
        print '</body></html>'
    def start_paragraph(self):
        print '<p>'
    def end_paragraph(self):
        print '</p>'
    def start_heading(self):
        print '<h2>'
    def end_heading(self):
        print '</h2>'
    def start_list(self):
        print '<ul>'
    def end_list(self):
        print '</ul>'
    def start_listitem(self):
        print '<li>'
    def end_listitem(self):
        print '</li>'
    def start_title(self):
        print '<h1>'
    def end_titile(self):
        print '</h1>'
    def sub_emphasis(self, match):
        return '<em>%s</em>' % match.group(1)
    def sub_url(self, match):
        return "<a href = '%s'>%s</a>"%(match.group(1),match.group(1))
    def sub_mail(self, match):
        return "<a href = 'mailto:%s'>%s</a>"%(match.group(1),match.group(1))
    def feed(self, data):
        print data
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rules.py:
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class Rule:
    def action(self, block, handler):
        handler.start(self.type)
        handler.feed(block)
        handler.end(self.type)
        return True
class HeadingRule(Rule):
    type = 'heading'
    def condition(self, block):
        return not '\n' in block and len(block)<=70 and not block[-1] == ':'
class TitleRule(HeadingRule):
    type = 'title'
    first = True
    def condition(self, block):
        if not self.first: return False
        self.first = False
        return HeadingRule.condition(self, block)
class ListItemRule(Rule):
    type = 'listitem'
    def condition(self, block):
        return block[0] == '-'
    def action(self, block, handler):
        handler.start(self.type)
        handler.feed(block[1:].strip())
        handler.end(self.type)
        return True
class ListRule(ListItemRule):
    type = 'list'
    inside = False
    def condition(self, block):
        return True
    def action(self, block, handler):
        if not self.inside and ListItemRule.condition(self,block):
            handler.start(self.type)
            self.inside = True
        elif self.inside and not ListItemRule.condition(self,block):
            handler.end(self.type)
            self.inside = False
        return False
class ParagraphRule(Rule):
    type = 'paragraph'
    def condition(self, block):
        return True
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markup.py:
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import sys, re
from handler import *
from util import *
from rules import *
class Parser:
    def __init__(self, handler):
        self.handler = handler
        self.rules = []
        self.filters = []
    def addRule(self, rule):
        self.rules.append(rule)
    def addFilter(self, pattern, name):
        def filter(block, handler):
            return re.sub(pattern, handler.sub(name), block)
        self.filters.append(filter)
    def parse(self, file):
        self.handler.start('document')
        for block in blocks(file):
            for filter in self.filters:
                block = filter(block, self.handler)
            for rule in self.rules:
                if rule.condition(block):
                    last = rule.action(block, self.handler)
                    if last: break
        self.handler.end('document')
class BasicTextParser(Parser):
    def __init__(self, handler):
        Parser.__init__(self,handler)
        self.addRule(ListRule())
        self.addRule(ListItemRule())
        self.addRule(TitleRule())
        self.addRule(HeadingRule())
        self.addRule(ParagraphRule())
        self.addFilter(r'\*(.+?)\*','emphasis')
        self.addFilter(r'(http://[\.a-zA-Z/]+)','url')
        self.addFilter(r'([\.a-zA-Z]+@[\.a-zA-Z]+[a-zA-Z]+)','mail')
handler = HTMLRenderer()
parser = BasicTextParser(handler)
parser.parse(sys.stdin)
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