sum = 0
n = 1
while True:
sum=sum+2**(n-1)
n=n+1
if n>21:
break
print sum
这样才是正确的代码
n = 1
while True:
sum=sum+2**(n-1)
n=n+1
if n>21:
break
print sum
这样才是正确的代码
2016-10-27
参考代码算出来的是第20项的数值 1048576 正确的应该是算出前20项值的累加
正确结果应该是 2097151
正确结果应该是 2097151
2016-10-27
print [x*100+y*10+z for x in range(1,10) for y in range(0,10) for z in range(0,10) if x==z]
2016-10-27
for x in range(0,9):
for y in range(1,10):
if x<y:
print x*10+y
for y in range(1,10):
if x<y:
print x*10+y
2016-10-27
d = { 'Adam': 95, 'Lisa': 85, 'Bart': 59, 'Paul': 74 }
sum = 0.0
for sc in d.values():
sum += sc
print sum*1.0/len(d)
sum = 0.0
for sc in d.values():
sum += sc
print sum*1.0/len(d)
2016-10-27
def greet(i='world'):
print 'Hello,'+i+'.'
greet()
greet('Bart')
print 'Hello,'+i+'.'
greet()
greet('Bart')
2016-10-27
d = {
'Adam': 95,
'Lisa': 85,
'Bart': 59
}
for x in d:
print str(x).lower()+':'+str(d[x])
'Adam': 95,
'Lisa': 85,
'Bart': 59
}
for x in d:
print str(x).lower()+':'+str(d[x])
2016-10-27