python - 编写程序生成日志

Question

我的文本文件

192.168.10.20 - - [18/Jul/2017:08:41:37 +0000] "PUT/search/tag/list HTTP/1.0"200 5042 "http://cooper.com/homepage/""Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/5342 (KHTML, like Gecko) Chrome/14.0.870.0 Safari/5342"
10.30.24.3 - - [18/Jul/2017:08:45:15 +0000]“POST/search/tag/list HTTP/1.0”200 4939“http://www.cole-brown.net/category/main/list/privacy/""Mozilla/5.0 (X11; Linux i686) AppleWebKit/5322 (KHTML, like Gecko) Chrome/14.0.843.0 Safari/5322"
98.5.45.3 - - [18/Jul/2017:08:45:49 +0000] "GET/apps/cart.jsp?appID=8471 HTTP/1.0"200 4958 "http://knight-chase.com/post .jsp""Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_7_3; rv:1.9.6.20) Gecko/2013-11-03 17:44:01 Firefox/3.8"
94.5.6.3 - - [18/Jul/2017:08:48:56 +0000] “GET/list HTTP/1.0” 200 4891 “http://thomas.com/explore/wp-content/homepage/” “Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_4; rv:1.9.5.20) Gecko/2013-02-19 05:36:22 Firefox/3.6.15"


预期来自用户的输入: 1) 生成的行数

2) 输出到文件或控制台

3) 在没有给出程序参数时提供帮助。

4) 确保程序生成的行数是该程序用户输入的行数。 (考虑大数)

python3 test.py --help(它应该显示帮助选项)

python3 test.py -N 20 -type console(它应该在控制台打印日志)

python3 test.py -N 10 -type log -name abc.log(它应该在文件中打印日志)

我的伪代码

 import sys
 from itertools import islice

 args = sys.argv
 print (args)
 #['file.py', 'datafile', '-N', '10']
 if args[1] == '-h':
     print ("-N for printing the number of lines: python file.py datafile -N 10")
 if args[2] == '-N':
     datafile = args[1]
     number = int(args[3])
     with open(datafile) as myfile:
         head = list(islice(myfile, number))
         head = [item.strip() for item in head]
         print (head)
         print ('\n'.join(head))

有没有比这更好的方法，比如argument passing

Answer 1

对于命令行参数，使用 Python 标准库 argparse :

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("type")
args = parser.parse_args()

if args.type == "console":
    print("log to console here")
elif args.type == "log":
    # log to file here
    pass