How can I create an array in python using a for loop?

Question

I have an array set out like this:

['age', 'height', 'weight']

and I need to "fill" the array with values from a list which contains objects with the values age, height and weight.

For example:

for value in list:
    age = value.age
    height = value.height
    weight = value.weight
    "[{}, {}m, {}lb]".format(age, height, weight)

and I would like to get the desired output:

[21, 1.77m, 160lb]
[25, 1.56m, 145lb]

etc for each object in the list.

So the final output would end up being like this:

['age', 'height', 'weight']
[21, 1.77m, 160lb]
[25, 1.56m, 145lb]

Thats what I have tried so far with the for loop, the value.age, etc works for getting the value but I can't get it to "fill" the containers with the values, without it getting rid of the previous container — user1825241
– user1825241, Commented Apr 23, 2013 at 22:14
Oh, sorry, I misunderstood. What does "list" look like when you print it? — Thomas Kelley
– Thomas Kelley, Commented Apr 23, 2013 at 22:19
Also, what are you actually doing with this statement: "[{}, {}m, {}lb]".format(age, height, weight)? You're calculating the format, but you don't seem to be doing anything with it (assigning it to a variable, printing it to screen, etc.). — Thomas Kelley
– Thomas Kelley, Commented Apr 23, 2013 at 22:23
Well it isn't being used to print it to the screen but I need to insert it into a html code, so I need the array to be a string that can then be implemented into the html code as a multiline string, if that makes sense. — user1825241
– user1825241, Commented Apr 23, 2013 at 22:28
If that's the case, you'll need to start with an empty string before the for loop, and append to it on each iteration. — Thomas Kelley
– Thomas Kelley, Commented Apr 23, 2013 at 22:42

radious · Accepted Answer · 2013-04-23 22:31:06Z

1

If I understand then you are looking for:

head = [['age', 'height', 'weight']]
for obj in obj_list: # overriding built-in list is a bad idea
    head += [obj.age, obj.height, obj.weight]

What will give you one array filled up with rest of the data:

[['age', 'height', 'weight'], 
 [21, 1.77m, 160lb], 
 [25, 1.56m, 145lb]]

Is this what you are looking for?

answered Apr 23, 2013 at 22:31

radious

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Comments

mariano · Accepted Answer · 2013-04-23 22:21:43Z

0

You can format the string like this:

In [5]: a, h, w = 10, 1.70, 200

In [7]: print "[%d, %.2fm, %dlb]" % (a, h, w)
------> print("[%d, %.2fm, %dlb]" % (a, h, w))
[10, 1.70m, 200lb]

Note that combining these values with string suffixes converts the elements to strings, which may or may not be good.

answered Apr 23, 2013 at 22:21

mariano

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