python 练习题

　　python是一个功能很强大的语言，他可以解决各种在数学问题，下面我分享一些练习题供大家参考：

有关正态分布的问题：

 1 # -*- coding: cp936 -*-
 2 import math
 3 a=0
 4 u=0
 5 x=0
 6 while 1:
 7     a =int(input("please input a :"))
 8     ifa<0:
 9        print "请重新输入："
10     elifa>0:
11        break;
12 u = int(input("please intput u :"))
13 x = int(input("please intput x :"))
14 fs =(1/math.sqrt(2*math.pi)*a)*math.exp(0.5*(math.pow(((x-u)/a),2)))
15 print "this fs is :%.2f"%fs;

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关于平抛运动矢量位移：

 1 v0 =10
 2 g= 9.81
 3 #t = int(input("please input a time:"))
 4 #h = v0*t+0.5*g*t**2
 5 #print "this h is :%.2f"%h;
 6 
 7 while 1:
 8     h =int(input("please input a hight:"))
 9     #h =v0*t+0.5*g*t**2
10     t1=(-v0+(v0**2-4*0.5*g*(-h))**0.5)/(2*0.5*g)
11     t2=(-v0-(v0**2-4*0.5*g*(-h))**0.5)/(2*0.5*g)
12     ift1>0:
13        print "this time1 is:%.2f"%t1;   
14     ift2>0:
15        print "this time2 is :%.2f"%t2;

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python的函数式编程

　　判断一个数是不是质数：

1  >>>f = lambda x:not reduce(lambda x,y:x or y,[x%i==0 for i inrange(2,x)])
2 >>> f(97)
3 True
4 >>> f(96)
5 False

　　求最大公约数：

1 >>> f = lambdam,n:[i for i in range(min(m,n),0,-1) if m%i==0 and n%i==0][0]
2 >>> f(123,77)
3 1
4 >>> f(125,100)
5 25

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计算给定数字的阶乘：

1 >>> f = lambdax:reduce(lambda x,y:x*y,[i for i in range(1,x+1)])
2 >>> f(5)
3 120

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1 >>> zip3 = lambdal1,l2,l3:[(l1[i],l2[i],l3[i]) for i in range(len(l1))]
2 >>>zip3([1,2,3],['a','b','c'],[1j,2j,3j])
3 [(1, 'a', 1j), (2, 'b', 2j), (3, 'c', 3j)]

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python的reduce函数的应用：

1 >>> f = lambdal:reduce(lambda x,y:x*y,l)
2 >>> f(l)
3 0
4 >>>f([1,2,2,3,4])
5 48

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蒙特卡洛近似求解

　　1.求圆周率：

 1 import random
 2 import math
 3 def round_(num):
 4     i=0
 5    number=0.0
 6     whilei<num:
 7        x = random.random()
 8        y = random.random()
 9       
10        y_=s(x)
11        if y<=y_:
12            number+=1
13        i+=1
14     return4*number/num
15 def s(a):
16     returnmath.sqrt(1-math.pow(a,2))

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　　2.求面积：

 1 import random
 2 def f(num):
 3     i=0
 4     s=0.0
 5     while i<num:
 6         x = random.random()
 7         #print x
 8         y = random.random()
 9         y_=ft(x)
10         if y<=y_:
11             s+=1
12         i+=1
13     return s/num
14   
15    
16 def ft(a) :
17     return a*a

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