while循环

 i=0 
while i<5:
    print("当前是第%d次执行循环"%(i 1)) 
    print("i=%d"%i)
    i =1

1. 计算1~100的累积和(包含1和100)

#encoding=utf-8
i=1
sum = 0
while i<=100:
   sum = sum   i i  = 1
   print("1~100的累积和为:%d"%sum)

while循环应用

2. 计算1~100之间偶数的累积和(包含1和100)

#encoding=utf-8
i=1
sum = 0 
while i<=100:
   if i%2 == 0:
      sum = sum   i
       i =1 
print("1~100的累积和为:%d"%sum)
     

while循环嵌套

while嵌套应用一

*
** 
*** 
**** 
*****

 i=1 
while i<=5:
   j=1 
   while j<=i:
      print("* ",end='')
       j =1
print("\n")
 i =1

while嵌套应用二:九九乘法表

i=1 
while i<=9:
	j=1
	while j<=i:
		print("%d*%d=%-2d "%(j,i,i*j),end='')
		j =1 
	print('\n')
	i =1