while循环：

# while 条件:
#     条件满足时做的事情

例子： 求1-100的和

i = 0
s = 0
while i < 100:print("第%d次" % i)i += 1  # 循环终止的条件s=s+iprint("和为%d" % s)

例子2： 猜1-100大小，并给出大小提示

import random
num = random.randint(1, 100)
flag = True
count = 0
while flag:guess_num = int(input("请输入你猜测的数字："))count += 1if guess_num == num:print("猜中了")flag = False  # 终止循环else:if guess_num > num:print("猜大了")else:print("猜小了")
print(f"总共猜测了{count}次")

while嵌套循环：

例子：九九乘法表

i = 1
while i <= 9:j = 1while j <= i:# \t :对齐     end=''  :print语句不换行print(f"{j}*{i}={i * j}\t", end='')j += 1i += 1# 输出换行print()

\t      : 对齐    
end=''  : print语句不换行