条件判断

简单if语句

>>>name='lily'>>>if name='lily':          print 'hello,', namehello,lily

if-else

>>>score=90>>>if score>=80:          print 'very good'else:    print 'keep trying'very good

if-elif-else

>>> age=18>>> if age>=18:	print 'adult'elif age<18:	print 'teenager'else:	print 'please enter the correct age'adult

循环

for

>>> L=[1,2,3,4,5]>>> for v in L:	print v12345

while

>>> a=0>>> while a<10:	a=a+1	print a12345678910

退出循环

break与continue区别：

break：退出循环体

利用 while True 无限循环配合 break 语句，计算 1 + 2 + 4 + 8 + 16 + ... 的前20项的和。

>>> s = 0>>> x = 1>>> n = 1>>> while True:	if n>20:		break	s=s+x	x=x*2	n=n+1	print s	13715316312725551110232047409581911638332767655351310712621435242871048575

continue：退出本次循环，不执行此次循环的循环体，继续下一个循环

>>> b=[0,1,2,6,3,4,1,5]>>> for v in b:	if v<2:		continue	print v	26345