s = set(['Adam', 'Lisa', 'Paul'])
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if not x in s:
s.add(x)
print s
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if not x in s:
s.add(x)
print s
2017-02-22
sum = 0
x = 1
while x<51:
sum=sum+2*x-1
x=x+1
print sum
x = 1
while x<51:
sum=sum+2*x-1
x=x+1
print sum
2017-02-22
L = []
x = 0
while x<100:
x = x+1
a = x*x
L.append(a)
print sum(L)
x = 0
while x<100:
x = x+1
a = x*x
L.append(a)
print sum(L)
2017-02-22