从 class 变量创建列表的有效方法。 (多个列表)
Efficient way to create a list a list from class variable. (multiple lists)
哪个例子会更快?
示例 1
A = []
B = []
C = []
for i in range(x, y):
A.append(obj[i].a)
B.append(obj[i].b)
C.append(obj[i].c)
示例 2
A = [obj[i].a for i in range(x, y)]
B = [obj[i].b for i in range(x, y)]
C = [obj[i].c for i in range(x, y)]
第一个:
- 第一个的复杂度是
O(n)
- 第二个的复杂度是
O(3n)
哪个例子会更快?
示例 1
A = []
B = []
C = []
for i in range(x, y):
A.append(obj[i].a)
B.append(obj[i].b)
C.append(obj[i].c)
示例 2
A = [obj[i].a for i in range(x, y)]
B = [obj[i].b for i in range(x, y)]
C = [obj[i].c for i in range(x, y)]
第一个:
- 第一个的复杂度是
O(n)
- 第二个的复杂度是
O(3n)