什么是列表推导式
如果我们有一个列表,并希望抽取列表中的元素,那么最标准的方法是使用 Python 循环,但是我们也可以直接通过列表推导式,它只需一行代码就能搞定所有操作。
基础列表推导式
import time
numberArr = [number for number in range(0, 1000000)]
start = time.time()
testArr = [i for i in numberArr]
end = time.time()
print(end - start) # 0.06299924850463867
start = time.time()
testArr = []
for i in numberArr:
testArr.append(i)
end = time.time()
print(end - start) # 0.15299725532531738
列表推导式+条件语句
import time
numberArr = [number for number in range(0, 1000000)]
start = time.time()
testArr = [i for i in numberArr if i % 8 == 0]
end = time.time()
print(end - start) # 0.05502510070800781
start = time.time()
testArr = []
for i in numberArr:
if i % 8 == 0:
testArr.append(i)
end = time.time()
print(end - start) # 0.08500814437866211