python re.sub(pattern,repl,string,count,flag)

re.sub(pattern,replacement,string,count,flags) 检索替换例1：import re phone = '134-9087-0987' obj = re.search(r'\D',phone) print obj.group() obj1 = re.sub(r'\D','',phone,count=1) print obj1  输出：- 1349087-0987 count数不指定时默认值为0，表示最大次数匹配 例2：def dashrepl(matchobj):     if matchobj.group(0) == '-': return '*'     else: return '&' print(re.sub('-{1,2}', dashrepl, 'pro----gram-files')) print(re.sub('-{1,3}', dashrepl, 'pro----gram-files')) 输出：pro&&gram*files pro&*gram*files {m,n}匹配前面一个字符m到n次。-{1,2}，表示匹配-字符1到2次，matchobj.group(0)匹配结果为-- text = "Professor Abdolmalek, please report your absences promptly." obj = re.search(r"(\w)(\w+)(\w)", text) if obj:     print 'all: ',obj.group()     print 'first: ',obj.group(1)     print 'second: ',obj.group(2)     print 'thid: ',obj.group(3) 输出：all:  Professor first:  P second:  rofesso thid:  r