python-04

>>> list('abcde')
['a', 'b', 'c', 'd', 'e']
>>> list(('abc', 123))
['abc', 123]
>>> str(['hello', 'world'])
"['hello', 'world']"
>>> tuple('abcde')
('a', 'b', 'c', 'd', 'e')
>>> alist = [32,54,234,436,221]
>>> for i, j in enumerate(alist):
...     print '#%s: %s' % (i, j)
... 
#0: 32
#1: 54
#2: 234
#3: 436
#4: 221
>>> max(alist)
436
>>> min(alist)
32
>>> len(alist)
5
>>> for i in reversed(alist):
...     print i,
... 
221 436 234 54 32
>>> sorted(alist)
[32, 54, 221, 234, 436]
>>> alist.reverse()
>>> alist
[221, 436, 234, 54, 32]
>>> alist.sort()
>>> alist
[32, 54, 221, 234, 436]
>>> zip ('abc', 'zxc')
[('a', 'z'), ('b', 'x'), ('c', 'c')]
>>> zip((1,2), ['abc', 'zxc'])
[(1, 'abc'), (2, 'zxc')]

#!/usr/bin/env python
import string
a = string.letters + '_'
nums = string.digits
print 'welcome to the...'
print 'test must be at least 2 chars long.'
b = raw_input('identifier to test? ')
if len(b) > 1:
    if b[0] not in a:
        print 'first symbol must be alphabetic'
    else:
        for c in b[1:]:
            if c not in a + nums:
                print 'other symbol must be aphanumeric'
                break
        else:
            print 'OK as an identifier.'

格式化输出

>>> print "%-8s%-15s%-12s" % ('name', 'email', 'moblie')
name    email          moblie      
>>> print "%-8s%-15s%-12s" % ('tom', 'tom@qq.com', '1234567890123')
tom     tom@qq.com     1234567890123
>>> print '%d' % 22
22
>>> print '%5d' % 22
   22
>>> print '%05d' % 22
00022
>>> print '%*s' % (10, 'tom')
       tom
>>> print '%*s' % (20, 'tom')
                 tom
>>> print '%-10s' % 'tom'
tom 

#!/usr/bin/env python
width = 48
data = []
while True:
    a = raw_input('enter data  . exit: ')
    if a == '.':
        break
    data.append(a)
print '+' + '*' * width + '+'
for i in data:
    b, c = divmod((width - len(i)), 2)
    print '+' + ' ' * b + i + ' ' * (b + c) + '+'
print '+' + '*' * width + '+'

改

#!/usr/bin/env python
width = 48
data = []
while True:
    a = raw_input('enter data  . exit: ')
    if a == '.':
        break
    data.append(a)
print '+' + '*' * width + '+'
for i in data:
    print '+' + i.center(width) + '+'
print '+' + '*' * width + '+'

>>> import string
>>> a = string.Template('$name is $age years old.')
>>> a.substitute(name = 'bob', age = 23)
'bob is 23 years old.'
>>> a.substitute(name = 'tom', age = 20)
'tom is 20 years old.'
>>> import os 
>>> os.system('ls /root/')

编写一个python脚本，添加一个用户，随机密码8位，并发送邮件给管理员

#!/usr/bin/env python
import string
import random
import os
allChs = string.letters + string.digits
a ="""your account is created.
username: $user
password: $pwd"""
def genPwd(num = 8):
    pwd = ''
    for i in range(num):
        pwd += random.choice(allChs)
    return pwd
if __name__ == '__main__':
    username = raw_input('username: ')
    password = genPwd()
    os.system('useradd %s' % username)
    os.system('echo %s | passwd --stdin %s' % (password,username))
    b = string.Template(a)
    os.system("echo '%s' |mail -s 'create user' root" % b.substitute(user = username, pwd = password))

>>> 'hello tom'.capitalize()        //将首字母大写
'Hello tom'
>>> 'hello tom'.center(20)        //设置居中
'     hello tom      '
>>> 'hello tom'.count('o')        //统计字母o出现的次数
2
>>> 'hello tom'.count('o',5)
1
>>> 'hello tom'.count('o', 0, 5)
1
>>> 'hello tom'.endswith('tom')        //检查字符串是否以tom作为结尾True
True
>>> 'hello tom'.startswith('hello')
True
>>> 'hello tom'.find('ll')        //查找ll出现的位置下标，找不到返回－1
2
>>> filename = ['hello', 'txt']
>>> '.'.join(filename)
'hello.txt'
>>> '    hello    '.strip()        //去掉字符串两端的空白
'hello'

>>> alist = []
>>> alist.append('hello')
>>> alist.append('hello')
>>> alist.append('bob')
>>> alist.count('hello')
2
>>> alist
['hello', 'hello', 'bob']
>>> alist.extend('new')
>>> alist
['hello', 'hello', 'bob', 'n', 'e', 'w']
>>> alist.extend(['new', 'line'])
>>> alist
['hello', 'hello', 'bob', 'n', 'e', 'w', 'new', 'line']
>>> alist.insert(1, 'abc')
>>> alist
['hello', 'abc', 'hello', 'bob', 'n', 'e', 'w', 'new', 'line']
>>> alist.pop()
'line'
>>> alist
['hello', 'abc', 'hello', 'bob', 'n', 'e', 'w', 'new']
>>> alist.pop(2)
'hello'
>>> alist
['hello', 'abc', 'bob', 'n', 'e', 'w', 'new']
>>> alist.remove('w')
>>> alist
['hello', 'abc', 'bob', 'n', 'e', 'new']
>>> alist.reverse()
>>> alist
['new', 'e', 'n', 'bob', 'abc', 'hello']
>>> alist.sort()
>>> alist
['abc', 'bob', 'e', 'hello', 'n', 'new']
>>> 

使用列表模拟栈结构

#!/usr/bin/env python
stack = []
def pushit():
    item = raw_input('enter item: ')
    stack.append(item)
def popit():
    if len(stack) == 0:
        print 'Empty stack'
    else:
        print 'pop', stack.pop(), 'from stack'
def viewstack():
    print stack
CMDs = {'p': pushit, 'o': popit, 'v': viewstack}
def showmenu():
    prompt = '''(P)ush
p()p
(V)iew
(Q)uit
please make a choice: '''
    while True:
        try:
            choice = raw_input(prompt).strip()[0].lower()
        except (KeyboardInterrupt, EOFError, IndexError):
            choice = 'q'
        if choice not in 'povq':
            continue
        if choice == 'q':
            break
        CMDs[choice]()
if __name__ == '__main__':
    showmenu()

>>> alist = ['age', 123]
>>> blist = alist
>>> blist[1] = 23    //注意，改变blist[1],alist[1]也会相应的被修改
>>> blist
['age', 23]
>>> alist            
['age', 23]
>>> alist = ['age', 123]
>>> blist = alist[:]
>>> blist[1] = 23        //修改了blist[1],alist[1]并不会被修改
>>> alist
['age', 123]
>>> blist
['age', 23]
>>> import copy
>>> alist = ['age', 123]
>>> blist = copy.copy(alist)
>>> blist
['age', 123]
>>> blist[1] = 25    //copy.copy实现了深拷贝，修改blist[1]，不会修改alist[1]
>>> blist
['age', 25]
>>> alist
['age', 123]

来自为知笔记(Wiz)