Python正則表達式小结(1)
学习一段python正則表達式了, 对match、search、findall、finditer等函数作一小结
以下以一段网页为例,用python正則表達式作一个范例:
strHtml = '''<div> <a href="/user/student/" class="user-t"><img src="/uploads/avatar/2015/06/082e408c-14fc-11e5-a98d-00163e02100b_big.jpg"></a> </div> </div> <div class="navbar-search-btn visible-xs visible-sm"> <a href="/common/mobile/search/" class="sch"></a> </div> ''' print strHtml #正則表達式 匹配如:< a href=”xxxxx” class=”xxxx” remod = re.compile(r"<a href=\"([^\"]*)\" class=\"([^\"]*)\"")
search方法举例
search 会查找第一个找到匹配字符串并返回
item = remod.search(strHtml) if item: print item.group() else: print "no match [search]" # 输出: # <a href="/user/student/" class="user-t"
match方法举例
match 会从字符串开头匹配查找第一个找到匹配字符串并返回
item = remod.match(strHtml, re.M|re.S) if item: print item.group() else: print "no match [match]"no match [match] # 输出 # no match [match]
findall方法举例
Findall查找全部找到匹配字符串并返回一个列表,假设有匹配的组(group),那么它是这个列表下的一个元组
items = remod.findall(strHtml) if items: print items for it in items: print it else: print "no match [findall]" # 输出 # [('/user/student/', 'user-t'), ('/common/mobile/search/', 'sch')] # ('/user/student/', 'user-t') # ('/common/mobile/search/', 'sch')
finditer方法举例
finditer查找全部找到匹配字符串并返回一个group,能够通过下标引用, 以下从1開始
tems = remod.finditer(strHtml if items: for it in items: print "it.group():",it.group() print "it.group(0):",it.group(0) print "it.group(1):",it.group(1) print "it.group(2):",it.group(2)+"\n" else: print "no match [findall]" # 输出 # it.group(): <a href="/user/student/" class="user-t" # it.group(0): <a href="/user/student/" class="user-t" # it.group(1): /user/student/ # it.group(2): user-t # it.group(): <a href="/common/mobile/search/" class="sch" # it.group(0): <a href="/common/mobile/search/" class="sch" # it.group(1): /common/mobile/search/ # it.group(2): sch