什么是计算列表最大值的更有效方法？

Question

I've been messing with Python a little bit and realized that I've been computing the max of a list the wrong way all this time !

This piece of code (which I've been using up to now :/)

mylist = [randint(0,1000) for _ in range(10**6)]
mymax = mylist[0]
for elm in mylist:
    mymax = max(elm, mymax)

takes 0.214785s to run, whereas this one

mymax = max(*mylist)

only 0.049693s !

The first one is more than four times slower. So I was wondering : Is there an even better way to compute the max of a list in python?

Answer 1

even better way ...

I have no idea if it's more performant, but you technically don't need to unpack the list:

mymax = max(mylist)

Answer 2

In your Python interpreter, type help(max) , you will get:

Help on built-in function max in module __builtin__:

max(...)
    max(iterable[, key=func]) -> value
    max(a, b, c, ...[, key=func]) -> value

    With a single iterable argument, return its largest item.
    With two or more arguments, return the largest argument.

max is written in C , so it should already fast enough, your issue is using it in a not very right way.

Answer 3

The simplest and best way to find max from the list is:

max(mylist)

You don't need to unpack the list.

Answer 4

您应该简单地写：

mymax = max(mylist)

Answer 5

Your code should just be these two lines.

mylist = [random.randint(0,1000) for _ in range(10**6)]
max_elm = max(mylist)

You do not have to trace through every element of the list. List has many associated functions with it. Use them. It would take it about 0.015854835510253906 seconds.