python tricks

1. 包裹传递

1.1 包裹

*和**分别标识元组和字典。如下两个例子，函数的所有参数被整合到一个元组/字典中。

def func(*name):
    print type(name)
    print name
func(1,4,6)
func(5,6,7,1,2,3)

def func(**dict):
    print type(dict)
    print dict
func(a=1,b=9)
func(m=2,n=1,c=11)

1.2解包裹

def func(a,b,c):
    print a,b,c
args = (1,3,4)
func(*args)

dict = {'a':1,'b':2,'c':3}
func(**dict)

2. print(3.0)

print(*objects, sep=' ', end='\n', file=sys.stdout)

from __future__ import print_function
....