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
2017-02-12
x1 = 1
d = 3
n = 100
s = 0
for i in range(n):
s = x1 + s
x1 = x1 +3
print (s)
d = 3
n = 100
s = 0
for i in range(n):
s = x1 + s
x1 = x1 +3
print (s)
2017-02-12
sum = 0
x = 2
n = 0
while True:
sum = sum + x ** n
n += 1
if n > 19:
break
print sum
x = 2
n = 0
while True:
sum = sum + x ** n
n += 1
if n > 19:
break
print sum
2017-02-12
两种解法:
sum = 0
x = 1
n = 1
while True:
sum = sum+x
if n >=20:
break
x = x*2
n = n+1
print sum
或者参考代码:
sum = 0
x = 1
n = 1
while True:
if n > 20:
break
sum = sum + x
x = x * 2
n = n + 1
print sum
sum = 0
x = 1
n = 1
while True:
sum = sum+x
if n >=20:
break
x = x*2
n = n+1
print sum
或者参考代码:
sum = 0
x = 1
n = 1
while True:
if n > 20:
break
sum = sum + x
x = x * 2
n = n + 1
print sum
2017-02-12
回复最高赞那个,因为你的sum、x、n都是放在if之前,所以你的判断条件是执行到第21项才停止,即你的sum算的是前21项了
2017-02-12
for x in ['1','2','3','4','5','6','7','8','9']:
for y in ['1','2','3','4','5','6','7','8','9']:
if x<y:
print x+y
照猫画虎
for y in ['1','2','3','4','5','6','7','8','9']:
if x<y:
print x+y
照猫画虎
2017-02-12