解析式是将一个容器类型的可迭代对象转换成另一个对应类型容器的工具。在转换过程中，可以指定元素必须符合一定的条件，才能添加至新的列表中，这样每个元素都可以按需要进行转换。
[返回值 for element in iterable [ if condition ]]
lst=[i for i in range(10)] print(lst)
运行结果
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
lst = [i for i in range(10) if i % 2] print(lst)
运行结果
[1, 3, 5, 7, 9]
lst = [i for i in range(10) if i % 2 if i % 3] print(lst)
运行结果
[1, 5, 7]
lst = [(i, j) for j in ‘abc‘ for i in range(3)] print(lst)
运行结果
[(0, ‘a‘), (1, ‘a‘), (2, ‘a‘), (0, ‘b‘), (1, ‘b‘), (2, ‘b‘), (0, ‘c‘), (1, ‘c‘), (2, ‘c‘)]
lst = [print("{} * {} = {:<2}".format(i, j, i * j), end=‘\n‘ if i==j else ‘ ‘) for i in range(1, 10) for j in range(1, i + 1)] print()
运行结果
1 * 1 = 1 2 * 1 = 2 2 * 2 = 4 3 * 1 = 3 3 * 2 = 6 3 * 3 = 9 4 * 1 = 4 4 * 2 = 8 4 * 3 = 12 4 * 4 = 16 5 * 1 = 5 5 * 2 = 10 5 * 3 = 15 5 * 4 = 20 5 * 5 = 25 6 * 1 = 6 6 * 2 = 12 6 * 3 = 18 6 * 4 = 24 6 * 5 = 30 6 * 6 = 36 7 * 1 = 7 7 * 2 = 14 7 * 3 = 21 7 * 4 = 28 7 * 5 = 35 7 * 6 = 42 7 * 7 = 49 8 * 1 = 8 8 * 2 = 16 8 * 3 = 24 8 * 4 = 32 8 * 5 = 40 8 * 6 = 48 8 * 7 = 56 8 * 8 = 64 9 * 1 = 9 9 * 2 = 18 9 * 3 = 27 9 * 4 = 36 9 * 5 = 45 9 * 6 = 54 9 * 7 = 63 9 * 8 = 72 9 * 9 = 81
原文：https://www.cnblogs.com/zh-dream/p/13732996.html