标签：style blog http io color ar 使用 sp for
变量命名：_num = 12 def myfunction (): global _num #引用全局变量 num = _num + 1 print 'myfunction num=' + str(num) myfunction()
>>> print repr(123L) 123L >>> print str(123L) 123
运算符
1）
>>> 5/6 0 >>> 5//6 0 >>> 5.0/6 0.8333333333333334 >>> 5.0//6 0.02）
>>> from __future__ import division >>> 5/6 0.8333333333333334 >>> 5//6 0 >>> 5.0/6 0.8333333333333334 >>> 5.0//6 0.03）
>>> -3**2 -9 >>> -(3**2) -9幂运算符（**）比取反运算符（一元减运算符）的优先级要高，所以-3**2和-(3**2)是等价的。
>>> True == 1 True >>> False == 0 True
i = 1
while i <= 5:
print('The ' + str(i) + '\'s print. ')
i += 1
else:
print('End...')array = [(1, 2), (3, 4), (5, 6)]
for (x, y) in array:
print(x, y);for line in open('test.txt'):
print linenames = ['admin', 'guest']
passwords = ['admin', 'guest']
for i in range(len(names)):
print("name: %s, password: %s" % (names[i], passwords[i]))names = ['admin', 'guest']
passwords = ['admin', 'guest']
for name, password in zip(names,passwords):
print("name: %s, password: %s" % (name, password))zip将两个序列“压缩”到一起，然后返回一个元组的列表。names = ['admin', 'guest']
for index, name in enumerate(names):
if 'admin' in name:
names[index] = 'root'
print("index: %s, name: %s" % (index, name))
print(names)enumerate的主要作用时在提供索引的地方迭代索引值对。name = 'admin' del name print name这个程序运行结果会报错：NameError: name ‘name‘ is not defined
name = 'admin' key = name del name print key这个程序运行结果为admin。移除name后并不影响key。因为python中删除的只是名称，而不是值本身。
exec "print 'hello'"执行结果为：hello
def function_name(arg1,arg2,....): statement return value其中，返回值不是必须的。如果没有return语句，则python默认返回值为None。
def login(username, password):
if (username == 'admin') and (password == 'admin'):
print 'login success!'
else:
print 'login error.....'可以使用如下语句调用：login('admin', 'admin')def login(username="guest", password="guest"):
if (username == 'admin') and (password == 'admin'):
print 'login success!'
else:
print 'login error.....'login('admin', 'admin')
login('admin')
login(password='admin')
login()login success! login error..... login error..... login error.....第一种方式提供了两个参数，将默认的两个值覆盖。
def print_array(names=[]):
for name in names:
print(name)
keys = ['admin', 'guest']
print_array(keys)def print_names(* names):
for name in names:
print(name)
print_names('root')
print_names('admin', 'guest')def print_key_value(** key_value):
keys = key_value.keys()
for key in keys:
print("key: %s, value: %s" % (key, key_value[key]))
print_key_value(username = 'admin', password = 'admin')运行结果：key: username, value: admin key: password, value: admin
标签：style blog http io color ar 使用 sp for
原文地址：http://blog.csdn.net/iam333/article/details/41243249
