python中列表推导式和集合推导式小案例

1.列表推导式小案例

# 创建一个列表
a_list = [x for x in range(10)]
print(a_list)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]


# 使用if判断语句,获取奇数
b_list = [x for x in range(10) if x%2==1]
print(b_list)
[1, 3, 5, 7, 9]


# 使用双层for循环
c_list = [(x,y) for x in range(2) for y in range(4)]
print(c_list)
[(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3)]


# 输出0~5之间的偶数和奇数的组合
odd_even_list = [(x, y) for x in range(6) if x%2==0 for y in range(6) if y%2==1]
print(odd_even_list)
[(0, 1), (0, 3), (0, 5), (2, 1), (2, 3), (2, 5), (4, 1), (4, 3), (4, 5)]


# 生成一个简单的4x4矩阵
matrix = [[x, x+3, x+5, x+7] for x in [2, 4, 6, 8]]
print(matrix)
[[2, 5, 7, 9], [4, 7, 9, 11], [6, 9, 11, 13], [8, 11, 13, 15]]


2.集合推导式的用法和列表推导式的用法相同，只需要将[]换成{}即可。

# 使用集合推导式输出0~5之间的偶数和奇数的组合
S = {(x, y) for x in range(6) if x%2==0 for y in range(6) if y%2==1}
print(S)
{(0, 1), (4, 5), (2, 1), (2, 5), (0, 5), (2, 3), (4, 3), (0, 3), (4, 1)}

# 其它类似，不再列举！