sum = 0
n = 0
while True:
sum=sum+2**n
n=n+1
if n>19:
break
print sum
n = 0
while True:
sum=sum+2**n
n=n+1
if n>19:
break
print sum
2017-02-13
sum = 0
n = 0
while True:
sum=sum+2**n
n=n+1
if n>19:
break
print sum
n = 0
while True:
sum=sum+2**n
n=n+1
if n>19:
break
print sum
2017-02-13
print后面不加u才能通过!!!
print '''静夜思
床前明月光,
疑是地上霜。
举头望明月,
低头思故乡。'''
print '''静夜思
床前明月光,
疑是地上霜。
举头望明月,
低头思故乡。'''
2017-02-13
L = list(range(1, 101))
print L[:10]
print L[2::3]
print L[4:50:5]
print L[:10]
print L[2::3]
print L[4:50:5]
2017-02-13
sum = 0
x = 1
n = 1
while True:
sum+=x
x*=2
n+=1
if n>20:
break
print sum
x = 1
n = 1
while True:
sum+=x
x*=2
n+=1
if n>20:
break
print sum
2017-02-13
def average(*args):
if args:
return(sum(args)*1.0/len(args))
else:
return 0.0
print average()
print average(1, 2)
print average(1, 2, 2, 3, 4)
if args:
return(sum(args)*1.0/len(args))
else:
return 0.0
print average()
print average(1, 2)
print average(1, 2, 2, 3, 4)
2017-02-13