python统计日志ip访问数的方法

import ref=open("/tmp/a.log","r")arr={} lines = f.readlines()for line in lines:   ipaddress=re.compile(r'^#(((2[0-4]/d|25[0-5]|[01]?/d/d?)/.){3}(2[0-4]/d|25[0-5]|[01]?/d/d?))')  match=ipaddress.match(line)  if match:     ip = match.group(1)     if(arr.has_key(ip)):       arr[ip]+=1     else:       arr.setdefault(ip,1) f.close() for key in arr:   print key+"->"+str(arr[key])

#111.172.249.84 - - [12/Dec/2011:05:33:36 +0800] "GET /images/i/goTop.png HTTP/1.0" 200 486 "http://wh.xxxx.com/" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)" #111.172.249.84 - - [12/Dec/2011:05:33:36 +0800] "GET /images/i/goTop.png HTTP/1.0" 200 486 "http://wh.xxxx.com/" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)" #111.172.249.85 - - [12/Dec/2011:05:33:36 +0800] "GET /images/i/goTop.png HTTP/1.0" 200 486 "http://wh.xxxx.com/" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)" #111.172.249.86 - - [12/Dec/2011:05:33:36 +0800] "GET /images/i/goTop.png HTTP/1.0" 200 486 "http://wh.xxxx.com/" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)" 

111.172.249.86->1111.172.249.84->2111.172.249.85->1

>>> a={} >>> a['key']='123' >>> print (a) {'key': '123'} >>> print (a.setdefault('key','456'))#显示a这个字典的'key'值的内容,因为字典有，所以不会去设置它 123 >>> print (a.setdefault('key1','456'))#显示a这个字典的'key1'值的内容，因为字典没有，所以设置为456了 456 >>> a {'key1': '456', 'key': '123'}