python day3

 

目录：

1.集合

2.文件操作

3.编码转换

4.函数

一.集合

 集合是无序的

list_1 = [1,4,5,7,3,6,7,9]
list_1 = set(list_1)

list_2 =set([2,6,0,66,22,8,4])
print(list_1,list_2)

执行结果：　　

#交集
print(list_1 & list_2)
#union
print(list_2 | list_1)

#difference
print(list_1 - list_2) # in list 1 but not in list 2

#对称差集
print(list_1 ^ list_2)

　　执行结果：

#添加一个
list_1.add(999)
#添加多个
list_1.update([888,777,555])
print(list_1)

　　执行结果：

#删除一个值
print(list_1.pop())
print(list_1.pop())

#删除指定值
list_1.discard(999)
print(list_1)

　　执行结果：

 二.文件操作

open文件的读写追加参数：

r ：读模式

w：写模式（清空原内容，在写入）

a：末尾追加模式

打开并读取文件：

f = open('test','r+',encoding='utf-8')
date = f.read()
print(date)
f.close()

打开文件追加内容

注意with open() 和上面打开读取文件的open() 都是 打开文件的方法，区别在于 with open()打开的文件在 with open()的子代码结束后会自动关闭文件

而open()打开的文件需要手动close()关闭

import time
time_format='%Y-%m-%d %X'　　#时间的格式%Y年 %m月 %d日 %X时分秒
time_current=time.strftime(time_format) #赋值当前时间到变量
with open('log','a') as f:
    f.write('%s hehehehe\n' %(time_current))

执行结果（类似于写日志）：

 文件修改

f = open("test","r",encoding="utf-8")
f_new = open("test_new","w",encoding="utf-8")
for line in f:　　#逐行读取文件内容
    if "楚风" in line:　　#比对 楚风 是否在内容中
        line = line.replace("楚风","水银灯") #replace 字符串的替换
    f_new.write(line)　　#把内容写入新的文件
f.close() #关闭文件
f_new.close()　　#关闭文件

执行结果：

 三.编码转换

一句话：非Unicode编码要想转换成其他编码 需要先decode()成Unicode，然后在encode()成要转换的编码

四.函数和过程

def 定义过程或者函数

 

#过程 = 没有return的函数,在ptyhon中过程会有一个隐式的返回值 return none
def func1():
    "双引号内写用途描述，可写可不写，建议写"
    print('you are super star...')
#函数
def func2(x):
　　"双引号内写用途描述，可写可不写，建议写"
    print(x)
    return 0
def func3(y,z):
    print('you are %s %s...' %(y,z))
    return 1,'syd',['a',1],{'福州':['仓山','鼓楼']}
def func4(d,e):
    print('you are %s %s...' %(d,e))
    return d
#默认参数 ，调用的时候不传g的值 则取默认值g=2 如果调用的时候传递g的值 则以传递的值为准
def func5(f,g=2):
    print(f,g)
    return 0
a = func1()
b = func2('hehed')
c = func3('super',1)
s = func4(e='super',d=1)

print(a)
print(b)
print(c)
print(s)
func5(6)
func5(6,99)

 

执行结果：

 函数的参数组（非固定个数的参数）

#参数组
#*args:接受N个位置参数，转换成元组形式
def test(*args):
    print(args)

test(1,2,3,4,5,5)　　#建议使用这种写法
test(*[1,2,4,5,5])#  args=tuple([1,2,3,4,5])

def test1(x,*args):
    print(x)
    print(args)

test1(1,2,3,4,5,6,7)

执行结果：

#**kwargs：接受N个关键字参数（格式：a=b），转换成字典的方式
def test2(**kwargs):
    print(kwargs)
    print(kwargs['name'])
    print(kwargs['age'])
    print(kwargs['sex'])

test2(name='alex',age=8,sex='F') #建议这种写法
test2(**{'name':'alex','age':8,'sex':'f'})
def test3(name,**kwargs):
    print(name)
    print(kwargs)

test3('alex',age=18,sex='m')

def test4(name,age=18,**kwargs):
    print(name)
    print(age)
    print(kwargs)

test4('alex',age=34,sex='m',hobby='tesla')

执行结果：

 

def test4(name,age=18,*args,**kwargs):
   print(name)
   print(age)
   print(args)
   print(kwargs)
   logger("TEST4")

def logger(source):
   print("from %s" %  source)

test4('alex',age=34,sex='#m',hobby='tesla')

执行结果：

 

 

程序练习 修改haproxy配置文件 

ha配置文件：

global       
        log 127.0.0.1 local2
        daemon
        maxconn 256
        log 127.0.0.1 local2 info
defaults
        log global
        mode http
        timeout connect 5000ms
        timeout client 50000ms
        timeout server 50000ms
        option  dontlognull

listen stats :8888
        stats enable
        stats uri       /admin
        stats auth      admin:1234

frontend oldboy.org
        bind 0.0.0.0:80
        option httplog
        option httpclose
        option  forwardfor
        log global
        acl www hdr_reg(host) -i www.oldboy.org
        use_backend www.oldboy.org if www

backend www.oldboy.org
        server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000

代码：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author:cmr
import sys, os


def backendlist(file):
    backend_list = []
    server_list = []
    backend_dict = {}
    backend_all = {}
    with open(file, "r+") as f:
        for line in f:
            line = line.strip()  # 去除字符串两边的空格
            if line.startswith('backend') == True:  # startswith字符串是否以backend开头
                server_list = []  # 清空server_list 以便把第二个backend下的所有server写入server_list
                # print(line)
                backend_name = line.split()[1]  # split 分割字符串为列表，默认以空格为分割符
                backend_list.append(backend_name)
                backend_all[backend_name] = []  # 字典中创建一个空值的key，不然删除server后该backend查询会报错提示没有该key
            elif line.startswith('server') == True:
                # print(line)
                backend_dict['servername'] = line.split()[1]
                backend_dict['ip'] = line.split()[2]
                backend_dict['weight'] = line.split()[4]
                backend_dict['maxconn'] = line.split()[6]
                server_list.append(backend_dict.copy())
                backend_all[backend_name] = server_list
                # print(backend_dict)
                # print('backend_list',backend_list)
                # print('backend_all',backend_all)
    return (backend_list, backend_all)


def show_backend(backendlist):  # 展示backend信息
    show_backend = {}
    (backend_list, backend_dict) = backendlist(file)
    print("欢迎使用haproxy配置工具".center(50, '-'))
    print("backend信息如下：")
    for index, bk_name in enumerate(backend_list):  # 获取列表值对应的index
        print(index, bk_name)
        show_backend[index] = bk_name
    return show_backend


def show_action_list():  # 展示操作清单
    content = '''操作清单：
1.查看backend和server信息
2.添加backend和server信息
3.修改backend和server信息
4.删除backend和server信息
5.退出
'''
    print("-".center(50, '-'))
    print(content)


def show_server_info(choice, backend_all, backend_list):  # 展示server信息
    serverinfo_list = []
    backend_name = backend_list[choice]
    for index, server_info in enumerate(backend_all[backend_name]):  # 取出该backend下的所有server节点信息
        info = ('server %s %s weight %s maxconn %s' \
                % (server_info['servername'], server_info['ip'], server_info['weight'], server_info['maxconn']))
        print(index, info)
        serverinfo_list.append(info)
    # print(serverinfo_list)
    return serverinfo_list


def back():
    flag = 0
    while flag != 'b':
        flag = input("操作完成，按b返回：")
        if flag == 'b':
            break
    return flag


def add():
    add_server = {}
    print("操作清单：")
    print("1.添加backend")
    print("2.添加server")
    choice = input("请选择操作编号：")
    if choice == '1':
        insert_backend_name = input("请输入新的backend：")
        backend_list.append(insert_backend_name)
        print(backend_list[-1], '添加成功!')
        servername = input("请输入%s下新增的server名称：" % (backend_list[-1]))
        ip = input("请输入%s下新增的ip：" % (backend_list[-1]))
        weight = input("请输入%s下新增的weight：" % (backend_list[-1]))
        maxconn = input("请输入%s下新增的maxconn：" % (backend_list[-1]))
        add_server['servername'] = servername
        add_server['ip'] = ip
        add_server['weight'] = weight
        add_server['maxconn'] = maxconn
        # print(add_server)
        print('--insert_backend_name--', insert_backend_name)
        print('--add_server--', add_server)
        with open(file, 'r') as f, open(new_file, 'w') as f_new:
            for line in f:
                f_new.write(line)
            f_new.write('\nbackend %s\n' % (insert_backend_name))
            f_new.write('\t\tserver %s %s weight %s maxconn %s\n'
                        % (add_server['servername'], add_server['ip'], add_server['weight'], add_server['maxconn']))
            return (insert_backend_name, add_server)
    elif choice == '2':
        flag = 0
        while flag != 'b':
            insert_backend_server = input("请输入要添加server的backend名字：")
            if insert_backend_server in (backend_list):
                servername = input("请输入%s下新增的server名称：" % (insert_backend_server))
                ip = input("请输入%s下新增的ip：" % (insert_backend_server))
                weight = input("请输入%s下新增的weight：" % (insert_backend_server))
                maxconn = input("请输入%s下新增的maxconn：" % (insert_backend_server))
                add_server['servername'] = servername
                add_server['ip'] = ip
                add_server['weight'] = weight
                add_server['maxconn'] = maxconn
                print(add_server)
                with open(file, 'r') as f, open(new_file, 'w') as f_new:
                    for line in f:
                        if line.strip() == 'backend %s' % (insert_backend_server):
                            f_new.write('backend %s\n' % (insert_backend_server))
                            f_new.write('\t\tserver %s %s weight %s maxconn %s\n'
                                        % (add_server['servername'], add_server['ip'], add_server['weight'],
                                           add_server['maxconn']))
                        else:
                            f_new.write(line)
                flag = 'b'
            else:
                print("backend 不存在...")
    else:
        print("参数错误！")


def backend_index_list():
    backend_index_list = []
    for index in showbackend:
        backend_index_list.append(index)
    return backend_index_list


def update():
    update_server = {}
    backend_num = input("请输入要修改的backend编号:")
    if backend_num.isdigit():
        backend_num = int(backend_num)
        if backend_num in backendindexlist:
            print('backend:', backend_list[backend_num])
            serverinfo = show_server_info(backend_num, backend_all, backend_list)
            long = len(serverinfo)
            # print(backend_all)
            update_choice = int(input("请选择要修改的server编号："))
            if update_choice >= 0 and update_choice < long:
                old_dict = backend_all[backend_list[backend_num]][update_choice]
                old_date = 'server %s %s weight %s maxconn %s' \
                           % (old_dict['servername'], old_dict['ip'], old_dict['weight'], old_dict['maxconn'])
                print(old_date)
                servername = input("请输入%s下修改的server名称：" % (backend_list[backend_num]))
                ip = input("请输入%s下修改的ip：" % (backend_list[backend_num]))
                weight = input("请输入%s下修改的weight：" % (backend_list[backend_num]))
                maxconn = input("请输入%s下修改的maxconn：" % (backend_list[backend_num]))
                update_server['servername'] = servername
                update_server['ip'] = ip
                update_server['weight'] = weight
                update_server['maxconn'] = maxconn
                update_dict = update_server
                update_date = '\t\tserver %s %s weight %s maxconn %s\n' \
                              % (update_dict['servername'], update_dict['ip'], update_dict['weight'],
                                 update_dict['maxconn'])
                # print(update_date)
                backend_all[backend_list[backend_num]][update_choice] = update_dict  # 修改的参数重新传入字典，更新数据
                print(backend_all)
                with open(file, 'r') as f, open(new_file, 'w') as f_new:
                    for line in f:
                        # line = line.strip()
                        if line.strip() == old_date:
                            f_new.write(update_date)
                        else:
                            f_new.write(line)
            else:
                print("编号不存在。。。")
        else:
            print("backend不存在...")
    else:
        print("请输入整数...")


def delete():
    update_server = {}
    backend_num = input("请输入要删除的backend编号:")
    if backend_num.isdigit():
        backend_num = int(backend_num)
        if backend_num in backendindexlist:
            print('backend:', backend_list[backend_num])
            serverinfo = show_server_info(backend_num, backend_all, backend_list)
            long = len(serverinfo)
            # print(backend_all)
            # print(backend_all[backend_list[backend_num]])
            update_choice = int(input("请选择要删除的server编号："))
            if update_choice >= 0 and update_choice < long:
                old_dict = backend_all[backend_list[backend_num]][update_choice]
                old_date = 'server %s %s weight %s maxconn %s' \
                           % (old_dict['servername'], old_dict['ip'], old_dict['weight'], old_dict['maxconn'])
                print(old_date)
                # print(backend_all[backend_list[backend_num]])
                # print(backend_all[backend_list[backend_num]])
                with open(file, 'r') as f, open(new_file, 'w') as f_new:
                    for line in f:
                        if line.strip() == old_date:
                            continue
                        else:
                            f_new.write(line)
            else:
                print("编号不存在。。。")
        else:
            print("backend不存在...")
    else:
        print("请输入整数...")


def check_empty_backend():
    for i in backend_all:
        if backend_all[i] == []:
            is_del = input("是否删除空backend节点：%s ：" % (i))
            if is_del == 'y':
                print(i)
                backend_all.pop(i)
                # print(backend_all)
                with open(file, 'r') as f, open(new_file, 'w') as f_new:
                    for line in f:
                        if line.strip() == 'backend %s' % (i):
                            continue
                        else:
                            f_new.write(line)
                write_and_back()
                return 'b'
    return 'n'

    # print(backend_all)


def write_and_back():
    os.rename(file, 'backup')
    os.rename(new_file, file)
    os.rename('backup', new_file)


# 主程序
flag = 0
file = 'test'
new_file = "%s_bakup" % (file)
exit_flag = '0'
while exit_flag != '5':
    (backend_list, backend_all) = backendlist(file)
    showbackend = show_backend(backendlist)
    backendindexlist = backend_index_list()
    show_action_list()
    active_num = input("请输入需要操作的编号：")
    if active_num == '1':  # -----------------查看
        choice = int(input("请选择backend编号："))
        print('%s ：' % (backend_list[choice]))
        show_server_info(choice, backend_all, backend_list)
        back()
    elif active_num == '2':  # -----------------添加
        add()
        write_and_back()
        back()
    elif active_num == '3':
        update()
        write_and_back()
        back()
    elif active_num == '4':
        back_flag = check_empty_backend()
        if back_flag == 'b':
            back()
            continue
        delete()
        write_and_back()
        back()
    elif active_num == '5':
        exit_flag = '5'
    else:
        print('参数错误！')
        back()