题目
题目请自己点击链接查看
坑点
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Python编写命令行程序库的选择，优先选 argparse
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因为argparse会自动为我们添加optional options，与题目要求会冲突。解决办法也很简单,禁用add_help：
p = argparse.ArgumentParser(add_help=False) -
题目要求的是支持
server.py add -h 127.0.0.1 -u shiyanlou -p shiyanlou这种方式的调用。命令的开头是没有Python的。所以你必须得在代码的第一行加上#! /usr/bin/python3。 -
VSCode如何对这种命令行参数的应用进行调试：修改lanuch.json，添加args字段，如下所示：
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with open('test2.py','a+') as f: # or ` for l in f:` for l in f.readlines(): print(l)上面的代码，执行你会发现没有输出。原因是当你以mode a+ 打开一个文件的时候：
The file pointer is at the end of the file if the file exists.
所以你得先 f.seek(0)(将文件指针移到开头)
题解
#! /usr/bin/python3
# -*- coding: utf-8 -*-
"""
@author: W@I@S@E
@contact: wisecsj@gmail.com
@site: https://wisecsj.github.io
@file: server.py
"""
import os, sys
import argparse
STORAGE_PATH = os.path.join(sys.path[0], 'serverinfo')
STORAGE_PATH_BAK = os.path.join(sys.path[0], 'serverinfo_bak')
def parser():
p = argparse.ArgumentParser(add_help=False)
# group = parser.add_mutually_exclusive_group()
p.add_argument("operation", help='add | delete | list')
p.add_argument('-h', help='server hostname')
p.add_argument('-u', help='username')
p.add_argument('-p', help='password')
return p
class NEParaException(Exception):
"""
Not Enough Para
"""
def __init__(self, err='Not Enough Para'):
super().__init__(err)
class NSOException(Exception):
"""
Not Support Operation
"""
def __init__(self, err='Not Support Operation'):
super().__init__(err)
class SSAException(Exception):
"""
Same Server Added
"""
def __init__(self, err='Same Server Added'):
super().__init__(err)
class ServerManager(object):
def __init__(self, parser_generate):
"""
:param parser_generate: func used to generate parser instance
"""
if not os.path.exists(STORAGE_PATH):
# os.mknod(STORAGE_PATH) not support on windows
with open(STORAGE_PATH, 'w'):
pass
self.parser = parser_generate()
self.args = self.parser.parse_args()
self.opr = self.args.operation
def _add(self):
h = self.args.h
u = self.args.u
p = self.args.p
if h and u and p:
with open(STORAGE_PATH, 'a+') as f:
f.seek(0)
for line in f:
exist_host = line.split()[0]
if h == exist_host:
raise SSAException
else:
f.write('{} {} {}\n'.format(h, u, p))
else:
raise NEParaException
def _list(self):
with open(STORAGE_PATH, 'r') as f:
for line in f:
print(line, end='')
def _delete(self):
with open(STORAGE_PATH, 'r') as f:
with open(STORAGE_PATH_BAK, 'w') as g:
h = self.args.h
g.writelines(line for line in f if h not in line)
os.remove(STORAGE_PATH)
os.rename(STORAGE_PATH_BAK, STORAGE_PATH)
def run(self):
try:
self.__getattribute__('_' + self.opr)()
except Exception as e:
print(e)
if __name__ == '__main__':
s = ServerManager(parser)
s.run()
PS： 有人知道为啥上面代码””” “"”内的一些文件和作者信息显示为啥不换行么？看着好难受。在简书和VSCode的markdown预览是可以正常换行显示的。 - -
