最新回答 / 不会换气的鱼
你需要返回去看7-3: return None可以简写为return。就是什么都不返回(或者说返回None),结束函数,不再执行下面的三行代码。用if else 可能逻辑会清楚一点<...code...>
2016-01-18
sum = 0
x = 1
while x <= 100:
sum += x
x += 2
print sum
x = 1
while x <= 100:
sum += x
x += 2
print sum
2016-01-18
def square_of_sum(L):
sum=0
for x in L:
sum=sum+x*x
return sum
print square_of_sum([1, 2, 3, 4, 5])
print square_of_sum([-5, 0, 5, 15, 25])
sum=0
for x in L:
sum=sum+x*x
return sum
print square_of_sum([1, 2, 3, 4, 5])
print square_of_sum([-5, 0, 5, 15, 25])
2016-01-18
L = [75, 92, 59, 68]
sum = 0.0
for score in L:
sum+=score
print sum / 4
sum = 0.0
for score in L:
sum+=score
print sum / 4
2016-01-18
L = [1*1]
x=2
while x<=100:
L.append(x*x)
x=x+1
print sum(L)
x=2
while x<=100:
L.append(x*x)
x=x+1
print sum(L)
2016-01-18
s = set(['Adam', 'Lisa', 'Paul'])
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if x in s:
s.remove(x)
else:
s.add(x)
print s
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if x in s:
s.remove(x)
else:
s.add(x)
print s
2016-01-18
s = set([('Adam', 95), ('Lisa', 85), ('Bart', 59)])
for x in s:
print x[0],':',x[1]
for x in s:
print x[0],':',x[1]
2016-01-18
months = set(['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'])
x1 = 'Feb'
x2 = 'Sun'
if x1 in months:
print 'x1: ok'
else:
print 'x1: error'
if x2 in months:
print 'x2: ok'
else:
print 'x2: error'
x1 = 'Feb'
x2 = 'Sun'
if x1 in months:
print 'x1: ok'
else:
print 'x1: error'
if x2 in months:
print 'x2: ok'
else:
print 'x2: error'
2016-01-18
上一次是ur'''.....'''弄成r'''...'''的错误,这次是倒叙索引越界的错误。
2016-01-18