s = '''Python was started in 1989 by \"Guido\".\nPython is free and easy to learn.'''
print s
print s
2016-05-21
L = ['Adam', 'Lisa', 'Bart']
L[-3] = 'Bart'
L[2] = 'Adam'
print L
L[-3] = 'Bart'
L[2] = 'Adam'
print L
2016-05-21
d = {
'Adam': 95,
'Lisa': 85,
'Bart': 59,
#first
#'Paul': 75
}
#second
#d.insert(2, 'Paul': 75)
d{'Paul': 75}
len(d)
'Adam': 95,
'Lisa': 85,
'Bart': 59,
#first
#'Paul': 75
}
#second
#d.insert(2, 'Paul': 75)
d{'Paul': 75}
len(d)
2016-05-20
d = {
'Adam': 95,
'Lisa': 85,
'Bart': 59,
}
d.insert(2, 'Paul': 75)
len(d)
'Adam': 95,
'Lisa': 85,
'Bart': 59,
}
d.insert(2, 'Paul': 75)
len(d)
2016-05-20
sum = 0
x = 0
while True:
x = x + 1
if x>100:
break
if x%2 == 0:
continue
sum = sum + x
print sum
x = 0
while True:
x = x + 1
if x>100:
break
if x%2 == 0:
continue
sum = sum + x
print sum
2016-05-20
sum = 0
x = 1
n = 1
while True:
sum = sum + x
x = 2 * x
n = n + 1
if n > 20:
break
print sum
x = 1
n = 1
while True:
sum = sum + x
x = 2 * x
n = n + 1
if n > 20:
break
print sum
2016-05-20
def square_of_sum(L):
sum=0
for x in L:
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+=x*x
return sum
print square_of_sum([1, 2, 3, 4, 5])
print square_of_sum([-5, 0, 5, 15, 25])
2016-05-20
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
2016-05-20
for x in range(1,9):
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
2016-05-20
while True:
sum = sum + x
x = x * 2
n = n + 1
if n > 20:
break
print sum
看似x和n没有联系 但是n循环20次 x一样跟着循环20次
sum = sum + x
x = x * 2
n = n + 1
if n > 20:
break
print sum
看似x和n没有联系 但是n循环20次 x一样跟着循环20次
2016-05-20