01Python基础_07函数

1 def add(x, y):
2     """Add two numbers.

　　　 The two values must be integers or strings"""　　#DocStrings
3     a = x + y
4     return a

def quad(x, a=1, b=0, c=0):
    return a*x**2 + b*x + c
print quad(2.0)    #省略有默认参数的参数，只给x赋值

print quad(2.0, b=3)    #给有默认参数的参数赋值

def add(x, *args):    #x后的参数当作一个元组中的元素
    total = x
    for arg in args:
        total += arg
    return total

print add(1, 2, 3, 4)    #可将参数理解成：1, (2, 3, 4)
print add(1, 2)

def add(x, **kwargs):    #**kwargs相当于一个字典
    total = x
    for arg, value in kwargs.items():
        print "adding ", arg
        total += value
    return total

print add(10, y=11, z=12, w=13)    #可以理解成：10, {y:11, z:12, w:13}

def add(x, y):
    """Add two numbers"""
    a = x + y
    return a
    
z = (2, 3)
print add(*z)    #"*"必不可少
w = {'x': 2, 'y': 3}
print add(**w)    #"**"必不可少

def sqr(x): 
    return x ** 2

a = [2,3,4]
print map(sqr, a)

def add(x, y): 
    return x + y

a = (2,3,4)
b = [10,5,3]
print map(add,a,b)