python练习

题1：求1+2!+3!+...+20!的和

t = 0for i in range(1, 21):    x = reduce(lambda x , y: x*y, range(1, i+1))    t += xprint t

题2：递归法求阶乘n！

def Factorial(n):    if n == 1 or n == 0:        return 1    else:        return n*Factorial(n-1)

题3：列表反转

<pre name="code" class="python">法1：for i in range(len(L)-1,-1,-1):    print L[i],

法2：print L[::-1]

例4：一个数如果恰好等于它的因子之和，这个数就称为"完数"。例如6=1＋2＋3.编程找出1000以内的所有完数。

for j in range(2,1001):    k = []    n = -1    s = j    for i in range(1,j):            if j % i == 0:                n += 1                s -= i                k.append(i)    if s == 0:        print j        for i in range(n):            print (str(k[i])),        print k[n]

例5：排序

L = [4, 8, 3, 5, 6, 9, 1, 2, 7, 0]for i in range(10):    m = i    for j in range(i+1, 10):        if L[m] > L[j]:            m = j    L[i], L[m] = L[m], L[i]print L

例6：求一个字符串最后一个单词的长度

data = raw_input("")print len(data.split()[-1])