def move(n,a,b,c)#n=2
if n==1 : #跳过
print a,'-->',c
return None
move(n-1,a,c,b)#n=2执行n-1后move（n-1，a,c,b）->move(1,a,c,b),跳到if处，执行print：a-->b
print a,'-->',c#执行print这里的a和c是指定义的函数的参数a和c打印结果是a-->c
move(n-1,b,a,c)#n=1执行n-1后跳到if处执行print此时a=b,c=c结果是：b-->c
move(2,'a','b','c')
if n==1 : #跳过
print a,'-->',c
return None
move(n-1,a,c,b)#n=2执行n-1后move（n-1，a,c,b）->move(1,a,c,b),跳到if处，执行print：a-->b
print a,'-->',c#执行print这里的a和c是指定义的函数的参数a和c打印结果是a-->c
move(n-1,b,a,c)#n=1执行n-1后跳到if处执行print此时a=b,c=c结果是：b-->c
move(2,'a','b','c')
2016-07-24
import math
def quadratic_equation(a, b, c):
if (b*b-4*a*c)<0 :
return None
else :
i=math.sqrt(b*b-4*a*c)
j=(-b+i)/(2*a),(-b-i)/(2*a)
return j
print quadratic_equation(2, 3, 0)
print quadratic_equation(1, -6, 5)
def quadratic_equation(a, b, c):
if (b*b-4*a*c)<0 :
return None
else :
i=math.sqrt(b*b-4*a*c)
j=(-b+i)/(2*a),(-b-i)/(2*a)
return j
print quadratic_equation(2, 3, 0)
print quadratic_equation(1, -6, 5)
2016-07-24
d = { 'Adam': 95, 'Lisa': 85, 'Bart': 59, 'Paul': 74 };
averge=sum(d.values())*1.0/len(d);
print averge;
averge=sum(d.values())*1.0/len(d);
print averge;
2016-07-24
sum = 0
x = 0
while True:
x = x + 1
if x > 100:
break
if x%2==0:
continue
sum+=x
print sum
x = 0
while True:
x = x + 1
if x > 100:
break
if x%2==0:
continue
sum+=x
print sum
2016-07-24
sum = 0
x = 1
n = 1
while True:
sum += x
n+=1
x *= 2
if n>20:
break;
print sum
x = 1
n = 1
while True:
sum += x
n+=1
x *= 2
if n>20:
break;
print sum
2016-07-24
x1 = 1
d = 3
n = 100
step = 1
x100 = 0
while step <= n:
x100 += x1
x1+=3
step+=1
print x100
d = 3
n = 100
step = 1
x100 = 0
while step <= n:
x100 += x1
x1+=3
step+=1
print x100
2016-07-24