嵌套循环以及其分解和举例

 1 '''width=int(input("width="))       
 2 height=int(input("height="))     #用户输入高度
 3 num_height=1
 4 while num_height<=height:
 5     num_width=1
 6     while num_width<=width:
 7         print("*",end=" ")
 8         num_width+=1
 9     print()
10     num_height +=1'''
11 
12 """width=int(input("width="))       #用户输入宽度
13 height=int(input("height="))
14 num_height=1
15 while num_height<=height:
16     print("*")
17     num_height+=1""" 
18     
19 """width=int(input("width="))       #用户输入宽度
20 height=int(input("height="))
21 num_height=1
22 while num_height<=height:
23     print("*",end=" ")
24     num_height+=1"""
25     
26 """num=4
27 while num>0:
28     print("####")
29     num-=1"""