eval函数就是实现list、dict、tuple与str之间的转化
str函数把list，dict，tuple转为为字符串
# 字符串转换成列表
a = "[[1,2], [3,4], [5,6], [7,8], [9,0]]" print(type(a)) b = eval(a) print(b) print(type(b)) 结果>> <class ‘str‘> [[1, 2], [3, 4], [5, 6], [7, 8], [9, 0]] <class ‘list‘>
# 字符串转换成字典
a = "{1: ‘a‘, 2: ‘b‘}" print(type(a)) b = eval(a) print(b) print(type(b)) 结果>> <class ‘str‘> {1: ‘a‘, 2: ‘b‘} <class ‘dict‘>
# 字符串转换成元组
a = "([1,2], [3,4], [5,6], [7,8], (9,0))" print(type(a)) b = eval(a) print(b) print(type(b)) 结果>> <class ‘str‘> ([1, 2], [3, 4], [5, 6], [7, 8], (9, 0)) <class ‘tuple‘>
原文：https://www.cnblogs.com/Hale-wang/p/10299942.html