Python练习题

冒泡排序

def bubbleSort(list):
    for i in range(len(list)):
        for j in range(i,len(list)):
            if list[i] > list[j]:
                list[i],list[j] = list[j],list[i]
    print list

求100以内的质数的倒数和

def prime(x):
    list = []
    for i in range(2,x):
        for j in range(2,i):
            if i%j == 0 :
                break
        else:
            list.append(i)
    return list

if __name__=='__main__':
    list = prime(100)
    print list
    sum = 0
    for i in range(len(list)):
        sum += 1/float(list[i])
    print sum

 

 

斐波那契数列

#递归

def fibonacci2(first,second,n):
    if n == 0 :
        return first
    elif n == 1:
        return second
    else:
        return fibonacci2(first,second,n-1)+fibonacci2(first,second,n-2)

 

if __name__=="__main__":
    for i in range(10):
        print(fibonacci2(1,1,i))

#迭代

def fibonacci(first,second,n):
    #result = 0
    #do something
    if n == 0 :
        return first
    elif n == 1:
        return second
    else:
        #sum = first + second
        sum = 0
        for i in range(n):
            sum = first + second
            first,second = second,sum
    return sum

 

if __name__=="__main__":
    for i in range(10):
        print(fibonacci(1,1,i))

 

最大公约数

def gcd(self,m,n):
    if not n:
        return m
    else:
        return self.gcd(n,m%n)

 

最小公倍数

def lcm2(self,x,y):
    if x*y == 0:
        return 0
    else:
        return int(x*y/self.gcd(x,y))

def lcm3(self,x,y):
    if x*y == 0:
        return 0

    if x > y:
        greater = x
    else:
        greater = y

    while greater%x or greater %y:
        greater+=1

    return greater

 

字符串翻转

s = "happy"
print s[::-1]

 

打开文档

 file = open（“filename”，“rwx”）

 

打开excel

import xlwt

book = xlwt.Workbook(encoding='utf-8', style_compression=0)

 

快速排序

def quick_sort(qlist):
    if qlist == []:
        return []
    else:
        qfirst = qlist[0]
        qless = quick_sort([l for l in qlist[1:] if l < qfirst])
        qmore = quick_sort([m for m in qlist[1:] if m >= qfirst])
        return qless + [qfirst] + qmore
qlist = quick_sort([4,5,6,7,3,2,6,9,8])
print qlist

#返回n以内所有数的阶乘的和
def fn(n):
    if n==1 :
        return 1
    else:
        return n*fn(n-1)

#求一个数的质因数
def zhiyinshu(m):
    if m<2:
        exit(0)
    else:
        for i in range(2,m+1):
            if m%i==0:
                print i
                return zhiyinshu(m/i)

#鸡兔同笼
总数x只，脚y只

def jitu(x,y):
    for ji in range(x+1):
        for tu in range(x+1):
            if (2 * ji + 4 * tu == y) and(ji+tu == x):
                print ji,tu
jitu(35,94)