Linux运维笔记|自动化运维攻城狮
一、模块的原理
- from os import system,popen
- from os import * 不推荐
- import commands
__init__.py
二、文件处理
- read 读 r
f = file("py_home_work.csv","r")
for line in f.readlines():
print line,
f.close()
- write 写 w
f = file("test.txt","w")
f.write("This is the first line\n")
f.write("This is the second line\n")
f.write("This is the third line\n")
f.close()
- append 追加 a
f = file("test.txt","a")
f.write("This is the appending part,i am different\n")
f.write("This is the appending part,i am different\n")
f.close()
- 修改
#read and write : r+ w+
f = file("test.txt","r+")
print 'first line:',f.readline()
print 'second line:',f.readline()
f.write("change third line")
print 'third:',f.readline()
f.close()
- f.tell 返回一个整数,表示当前文件指针的位置
- f.seek 用来移动文件指针
- 另一种打开方式
with open("test.txt","r") as f:
f.seek(0)
data = f.readlines()
三、自动更改文件内容
- 将指定的字符串，替换成新的字符串 [此方法只能替换相同长度的字符串]
#!/usr/bin/python
import sys
if len(sys.argv) < 2:
print len(sys.argv)
print "exit"
if '-r' in sys.argv:
rep_argv_pos = sys.argv.index('-r')
find_str = sys.argv[rep_argv_pos + 1] #原字符串
new_str = sys.argv[rep_argv_pos + 2] #新字符串
else:
print "argv is not exist"
exit()
f = file('passwd','r+')
while True:
line = f.readline()
if find_str in line:
#指定字符串起始位置 = 当前位置 - 当前行的字符长度
last_line_pos = f.tell() - len(line)
#跳到指定字符串的前一行最后的位置
f.seek(last_line_pos)
# 将指定字符串修改为新字符串
new_line = line.replace(find_str,new_str)
print new_line
f.write(new_line)
break
f.close()
- 使用fileinput模块修改
# inplace = 1 时修改才会写到文件里，默认等于0时只会在内存里修改
>>> import fileinput
>>> for line in fileinput.input("passwd",inplace=1):
... print line.replace("man","MAN")
# 修改原文件并，并把原文件备份一个.bak结尾的文件
>>> for line in fileinput.input("passwd",inplace=1,backup='.bak'):
... print line.replace("MAN","leoiceo")
四、字符编码
- ASCII Unicode Utf-8
- 字符编解码的故事
- 编写python代码前在开头加上
#_*_coding:utf-8_*_ - Unicode 在中文字符前加上小u
print u'你好，世界'
五、列表
- list的方法
L.append(var) #追加元素
L.insert(index,var)
L.pop(var) #返回最后一个元素，并从list中删除之
L.remove(var) #删除第一次出现的该元素
L.count(var) #该元素在列表中出现的个数
L.index(var) #该元素的位置,无则抛异常
L.extend(list) #追加list，即合并list到L上
L.sort() #排序
L.reverse() #倒序
a[1:] #片段操作符，用于子list的提取
[1,2]+[3,4] #为[1,2,3,4]。同extend()
[2]*4 #为[2,2,2,2]
del L[1] #删除指定下标的元素
del L[1:3] #删除指定下标范围的元素
- list的复制
L1 = L #L1为L的别名，用C来说就是指针地址相同，对L1操作即对L操作
L1 = L[:] #生成L的一个COPY
- 购物车小练习
- 初版
products = ["apple","bike","Telas","Coffee"]
prices = [ 3000,1900,80000,35 ]
print "==========Welcome to leoiceo pyshop!========="
mymoney = int(raw_input("Please input your money: "))
buy_list = []
while True:
for p in products:
pindex = products.index(p)
print
print pindex,p,prices[pindex]
buy_pro = int(raw_input("Please input you want buy product: "))
if products[buy_pro] in products and mymoney > int(prices[buy_pro]) :
mymoney = mymoney - int(prices[buy_pro])
buy_list.append(products[buy_pro])
print "--->buy %s,you money only %s" % (products[buy_pro],mymoney)
else:
print "You Not enough money,only money: %s" % mymoney
for bl in buy_list:
print "You buy product list: %s\n" % bl
break
- 优化版
__author__ = 'leoiceo'
#_*_coding:utf-8_*_
products = [
['Apple',5000],
['Ipad',3500],
['Tesla',800000],
['Coffee',35],
['Clothes',500],
['Shoses',800],
]
salary = 9000
shop_list = []
while True:
print 'Please choise your want buy:'
for index,p in enumerate(products):
print ''' %s %s price %s''' % (index,p[0],p[1])
choise = raw_input("Choose sth to buy: ").strip()
if choise.isdigit():
choise = int(choise)
p_price = products[choise][1]
if p_price < salary:
shop_list.append(products[choise])
salary -= p_price
print "Has added \033[31;1m%s\033[0m into shop list,your current balance is \033[31;1m%s\033[0m" \
% (products[choise][0],salary)
else:
print "\033[41;1mMony is not enough,try thing else jera!\033[0m"
elif choise == 'quit':
print "-----shopping list --------"
for k,v in enumerate(shop_list):
print k,v
print "Your current balance is \033[31;1m%s\033[0m" % salary
print "-------------bye-------------"
break
六、字典
- 方法
D.get(key, 0) #同dict[key]，多了个没有则返回缺省值，0。[]没有则抛异常
D.has_key(key) #有该键返回TRUE，否则FALSE
D.keys() #返回字典键的列表
D.values() #以列表的形式返回字典中的值，返回值的列表中可包含重复元素
D.items() #将所有的字典项以列表方式返回，这些列表中的每一项都来自于(键,值),但是项在返回时并没有特殊的顺序
D.update(dict2) #增加合并字典
D.popitem() #得到一个pair，并从字典中删除它。已空则抛异常
D.clear() #清空字典，同del dict
D.copy() #拷贝字典
D.cmp(dict1,dict2) #比较字典，(优先级为元素个数、键大小、键值大小)
#第一个大返回1，小返回-1，一样返回0
dictionary的复制
dict1 = dict #别名
dict2=dict.copy() #克隆，即另一个拷贝。
列表VS字典
- dict:
查找和插入的速度极快，不会随着key的增加而增加 需要占用大量的内存，内存浪费多。 KEY不可变
默认无序 - list
查找和插入的时间随着元素的增加而增加 占用空间小，浪费内存很少 通过下标查询 有序
- dict:
用字典做多级菜单
menu = {
"Beijing" :{
"Chaoyang":{
"CBD":["CCIC","CCTV"],
"WangJing":["Momo","ChuiZi"]
},
"HaiDian": ["Baidu","YouKu"]
},
"Shanghai":{
"PuDong":["Ctrip","1 shop"],
"PuXi":["China Bank","America Bank"]
}
}
exit_flag = False
while not exit_flag:
for index,key in enumerate(menu.keys()):
print index,key
choise_1 = raw_input("please choise your like city: ")
if choise_1.isdigit():
choise_1 = int(choise_1)
key_1 = menu.keys()[choise_1]
print key_1
while not exit_flag:
for index,key in enumerate(menu[key_1]):
print '--->',index,key
choise_2 = raw_input("Please choise your like area: ")
if choise_2.isdigit():
choise_2 = int(choise_2)
key_2 = menu[key_1].keys()[choise_2]
#print key_2
while not exit_flag:
for index,key in enumerate(menu[key_1][key_2]):
print '-->-->',index,key
choise_3 = raw_input("Please choise your like company: ")
if choise_3.isdigit():
print "This is the last level....."
elif choise_3 == "quit":
exit_flag = True
elif choise_3 == "back":
break
else:
print "-----going to quit-----"