newbee: simple python for loop question

[jobs]

test = [random.randint(1,10) for i in range(20)]

Can someone what does the random.randint(1,10) fron to for loop does, and the square brackets around it means, make it a list?

[StrikerX11]

test = [random.randint(1,10) for i in range(20)]

equals

>>> import random
>>> test=[]
>>> for i in range(20):
    #test.append(random.randint(1, 10))
    random_int=random.randint(1, 10)
    test.append(random_int)

[grobister]

It should give you a list of 20 random numbers between 1 and 10

e.g. [3,6,7,1,9.......]

It's not really written the "python way" which encourages transparent readable code!

hth

:-D

[jrcagle]

The square brackets are part of a construction called a 'list comprehension'. The basic syntax is

[x for blah in yourlist]

The idea is to create a list quickly in one line. And as StrikerX11 noted, it's exactly the same as

tmp = []
for blah in yourlist:
    tmp.append(x)

(Usually, x and blah have some relationship to each other, but as you can see in this case, not always).

It's not really written the "python way" which encourages transparent readable code!

I wonder what the clearest way to write that would be. I found myself saying, "That's how I'd do it..."

Jeff

[vegaseat]

Once you get familiar with constructs like list comprehension, they become quite easy to read. List comprehensions also give quite an improvement in speed too.