四个python小练习

四个python小练习：

1、打印出1-100之间的所有偶数

<pre class="brush:python;gutter:true;">def even_print():
    
for i in range(1,101):
       
 if i % 2 == 0:
            
print (i)
even_print()
#列表解析式的方式：
k = [n for n in range(1,101) 
if n%2 == 0]
print (k)

2、设计一个函数，在桌面上创建10个文件，并以数字命名

def text_creation():    
path = 'C:/Users/Administrator/Desktop'    
for name in range (1,11):        
    with open(path + str(name) + '.txt','w') as text:                
       text.write(str(name))                
       text.close()            
print ('done')text_creation()

3、复利计算函数

def invest(amount,rate,time):
    print('principal amount:{}'.format(amount))    
    for t in range(1,time + 1):
        amount = amount * (1 + rate)        
        print ('year {}: ${}'.format(t,amount))
invest(100,.05,8)
invest(2000,.025,5)

4、随机验证码

import random
checkcode = ''
for i in range(4):
   current = random.randrange(0,4)    
   if current != i:
       temp = chr(random.randint(65,90))    
   else:
       temp = random.randint(0,9)
   checkcode += str(temp)
print (checkcode)