python笔记：函数

#!python
#filename func_local.py
x=50

def func(x):
    print('x is',x)
    x=2
    print('Changed local x to',x)

func(x)
print('x is still',x)

#!python
#filename func_global.py
x=50
def func():  
    global x
    print('x is ',x)    
    x=2
    print('changed global x to',x)

func()
print('Value of x is ',x)

#!python
#filename func_default.py
def say(message, times=1):
    print(message*times)

say('Hello')
say('Hello ',5)

#!python
#filename func_key.py
def func(a,b=5,c=10):
    print('a is',a,'and b is',b,'and c is',c)

func(3,7)
func(25,c=24)
func(c=50,a=100)

#!python
#filename total.py
def total(initial=5,*numbers,**keywords):
    count=initial
    for number in numbers:
        count+=number
    for key in keywords:
        count+=keywords[key]
    return count

print(total(10,1,2,3,vegetable=50,fruits=100))

#!python
#filename keyword_only.py
def total(initial=5,*numbers,extra_number):
    count=initial
    for number in numbers:
        count+=number
    count+=extra_number
    print(count)

total(10,1,2,3,extra_number=50)
total(10,1,2,3)

66
Traceback (most recent call last):
  File "keyword_only.py", line 11, in <module>
    total(10,1,2,3)
TypeError: total() missing 1 required keyword-only argument: 'extra_number'

#!python
#filename func_return.py
def func1():
    x=5
    return x
def func2():
    pass
def func3():
    print('I do nothing here')
print(func1())
print(func2())
print(func3())

#!python
#file name func_doc.py
def printMax(x,y):
    '''Prints the maximum of two number.

    The two values must be integers.'''
    x=int(x)
    y=int(y)

    if x>y:
        print(x,'is maximum')
    else:
        print(y,'is maximum')

printMax(3,5)
print(printMax.__doc__)