python简单实例训练(21~30)

# -*- coding: UTF-8 -*-
while True:
 n = input("请输入一个数:")
 #这里有逗号是为了保证它输出后不自动换行，下同
 print '{} = '.format(n), 
 #判断你输入的是不是正确格式
 if not isinstance(n, int) or n <= 0 :
  print '请输入一个正确的数字 !' 
 #如果你是输入的是 1，那只输出 1
 if n in [1] : 
  print '{}'.format(n) 
 while n >= 2:
  for i in range(2,n + 1):
   if n % i == 0:
    n /= i  #n 等于 n/i
    if n == 1: 
     print i ,
    else :  # index 一定是素数
     print '{} *'.format(i),
    break
 print  #换行咯

# -*- coding: UTF-8 -*-
def reduceNum(n):
 print '{} = '.format(n),
 if not isinstance(n, int) or n <= 0 :
  print '请输入一个正确的数字 !'
  exit(0)
 elif n in [1] :
  print '{}'.format(n)
 while n not in [1] : # 循环保证递归
  for i in range(2, n + 1) :
   if n % i == 0:
    n /= i # n 等于 n/i
    if n == 1: 
     print i 
    else : # i 一定是素数
     print '{} *'.format(i),
    break

reduceNum(100)
reduceNum(9)

# -*- coding: UTF-8 -*-
while True:
 x = input("pls input a number:")
 ret = []
 while x > 1:
  for v in range(2,x + 1):
   if x % v == 0:
    ret.append(v)
    x /= v
    break
 print ret

 输出：
  pls input a number:9
  [3, 3]

# -*- coding: UTF-8 -*-
Tn = 0
Sn = [] #用来存储数字个数
n = int(raw_input('输入你想要相加的数字个数 n = :')) #控制你要相加的次数
a = int(raw_input('输入数字 a = :')) #真正要加的数字
for count in range(n):
 Tn = Tn + a 
 a = a * 10
 Sn.append(Tn)#每加一个数就放在Sn列表中
 print Tn

 #lambda这个函数比较强大，具体用法可以看下资料
Sn = reduce(lambda x,y : x + y,Sn)
print Sn

# -*- coding: UTF-8 -*-
import random
import time

while True:
 x = random.randint(1,1000)
 #因为后面求质数要修改x的值，所以先把x保存起来备用
 s = x 
 factors = [1] #1是任何数的因子
 while x > 1:
  #上限取值可以是x，即因子也可以是x本身，这个大家都懂得
  for v in range(2,x + 1):
   if x % v == 0:
    factors.append(v) 
    #找到了当前的最小因子，重置继续找下一符合条件的最小因子
    x /= v
    #由于break是跳出当前的循环，所以这里的break是跳出for循环
    break
 print "所有因子是 %s,所以"%(factors),
 if sum(factors) == s: #这里就是判断函数了
  print "%d 是完数"%(s)
 else:
  print "%d 不是完数"%(s)
time.sleep(1) #为防止程序卡顿，我睡一秒输出一个

# -*- coding: UTF-8 -*-

for i in range(ord('x'),ord('z') + 1):
 for j in range(ord('x'),ord('z') + 1):
  if i != j:
   for k in range(ord('x'),ord('z') + 1):
    if (i != k) and (j != k):
     if (i != ord('x')) and (k != ord('x')) and (k != ord('z')):
      print 'order is a -- %s\t b -- %s\tc--%s' % (chr(i),chr(j),chr(k))

# -*- coding: UTF-8 -*-

a = 2.0  #第一个数的分母
b = 1.0  #第一个数的分子
s = 0   #前20项的和
for n in range(1,21):
 s += a / b
 t = a  #先把分子保存到t
 a = a + b #分子是前一个分数的分子分母之和
 b = t  #分子分母交换
print s

# -*- coding: UTF-8 -*-

a = 2.0
b = 1.0
s = 0.0
for n in range(1,21):
 s += a / b
 b,a = a , a + b
print s

# -*- coding: UTF-8 -*-

a = 2.0
b = 1.0
l = []
for n in range(1,21):
 b,a = a,a + b
 l.append(a / b)
print reduce(lambda x,y: x + y,l)

 # -*- coding: UTF-8 -*-

n = 0
s = 0
t = 1
for n in range(1,21):
 t *= n #这里t就是20以内每个数的阶乘
 s += t #把每次得到的阶乘值加到s
print '1! + 2! + 3! + ... + 20! = %d' % s

# -*- coding: UTF-8 -*-

s = 0
l = range(1,21)
def op(x):
 r = 1
 for i in range(1,x + 1):
  r *= i
 return r

s = sum(map(op,l)) 
print '1! + 2! + 3! + ... + 20! = %d' % s

# -*- coding: UTF-8 -*-
ls = [1,2,3]
rs = map(str, ls)
#打印结果 ['1', '2', '3']

lt = [1, 2, 3, 4, 5, 6]
def add(num):
 return num + 1

rs = map(add, lt)
print rs 
#打印结果[2,3,4,5,6,7]

# -*- coding: UTF-8 -*-
def jiecheng(n):
 if n <= 1:
  return 1
 else:
  return n * jiecheng(n-1)
print jiecheng(5)

输出：120

# -*- coding: UTF-8 -*-

def output(s,l):
 if l==0:
  return
 print (s[l-1])
 output(s,l-1)

s = raw_input('Input a string:')
l = len(s)
output(s,l)

# -*- coding: UTF-8 -*-
a = [1,2,3,4,5]
a.reverse()
print a

 或者：

# -*- coding: UTF-8 -*-
s = list(raw_input('Input a string:'))
s.reverse()
print s

# -*- coding: UTF-8 -*-
x = 10
for i in range(1,5):
 x = x + 2
print x

# -*- coding: UTF-8 -*-
def age(n):
 if n == 1: 
  x = 10
 else: 
  x = age(n - 1) + 2
 return x
print age(5)

# -*- coding: UTF-8 -*-
a = int(raw_input("请输入一个数字:"))
x = str(a)
flag = True

for i in range(len(x)/2):
 if x[i] != x[-i - 1]: #如果不相等，直接跳出循环，直接判断不是回文数
 flag = False
 break
if flag:
 print "%d 是一个回文数!" % a
else:
 print "%d 不是一个回文数!" % a

# -*- coding: UTF-8 -*-

 letter = raw_input("please input:")
 #while letter != 'Y':
 if letter == 'S':
  print ('please input second letter:')
  letter = raw_input("please input:")
  if letter == 'a':
   print ('Saturday')
  elif letter == 'u':
   print ('Sunday')
  else:
   print ('data error')

 elif letter == 'F':
  print ('Friday')

 elif letter == 'M':
  print ('Monday')

 elif letter == 'T':
  print ('please input second letter')
  letter = raw_input("please input:")

  if letter == 'u':
   print ('Tuesday')
  elif letter == 'h':
   print ('Thursday')
  else:
   print ('data error')

 elif letter == 'W':
  print ('Wednesday')
 else:
  print ('data error')