python练习

 

使用while语句：
number=23
running=True
while running:
    guess=int(raw_input('Enter an integer:'))
    if guess==number:
        print 'Congratulations,you guessed it.'
        running=False# this causes the while loop to stop
    elif guess<number:
            print 'No,it is a little higner than that'
    else:
            print 'No,it is a little lower than that'
else:
    print 'The while loop is over.'
print 'Done'

#使用for语句
for i in range(1,5):
    print i
else:
    print'The for loop is over.'

#使用break语句
while True:
    s=raw_input('Enter something:')
    if s=='quit':
        break
    print 'Length of the string is',len(s)
print 'Done'

#使用continue语句
while True:
    s=raw_input('Enter something:')
    if s=='quit':
        break
    if len(s)<3:
        continue
    print 'Input is of sufficient length

#定义函数
def sayHello():
    print 'Hello World!'# block belonging to the function
sayHello() #call the function

#使用函数形参
def  printMax(a,b):
    if a>b:
        print a, 'is maximum'
    else:
        print b,'is maximum'
printMax(3,4)#directly give literal values
x=5
y=7
printMax(x,y)#give variables as arguments

#使用局部变量
def func(x):
    print 'x is',x
    x=2
    print 'Changed local x to',x
x=50
func(x)
print'x is still',x

#使用global语句
def func():
    global x
    print 'x is',x
    x=2
    print 'Changed local x to',x
x=50
func()
print 'Valued of x is',x

#使用默认参数值
def say(message,times=1):
    print message*times
say('Hello')
say('World',5)

#使用关键参数
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)

#使用字面意义的语句
def maximum(x,y):
    if x>y:
        return x
    else:
        return y
print maximum(2,3)