a = [{'a','b','c'},'a',['a','b','c'],('a','b','b'),1,{1:'A',2:'b',3:'C'},1.25]
length = len(a)
i = 0
count = 0
while not isinstance(a[i], bool):
count += 1
print(count,a[i],'-->',type(a[i]))
i += 1
i %= length
if count== 20:
print('已经循环20次了,退出吧。')
break
## 1 {'c', 'b', 'a'} --> <class 'set'>
## 2 a --> <class 'str'>
## 3 ['a', 'b', 'c'] --> <class 'list'>
## 4 ('a', 'b', 'b') --> <class 'tuple'>
## 5 1 --> <class 'int'>
## 6 {1: 'A', 2: 'b', 3: 'C'} --> <class 'dict'>
## 7 1.25 --> <class 'float'>
## 8 {'c', 'b', 'a'} --> <class 'set'>
## 9 a --> <class 'str'>
## 10 ['a', 'b', 'c'] --> <class 'list'>
## 11 ('a', 'b', 'b') --> <class 'tuple'>
## 12 1 --> <class 'int'>
## 13 {1: 'A', 2: 'b', 3: 'C'} --> <class 'dict'>
## 14 1.25 --> <class 'float'>
## 15 {'c', 'b', 'a'} --> <class 'set'>
## 16 a --> <class 'str'>
## 17 ['a', 'b', 'c'] --> <class 'list'>
## 18 ('a', 'b', 'b') --> <class 'tuple'>
## 19 1 --> <class 'int'>
## 20 {1: 'A', 2: 'b', 3: 'C'} --> <class 'dict'>
## 已经循环20次了,退出吧。
## 这个意思??