Python: Assaign values to variables using two lists

Question

How can I assign values to variables by using two lists:

Numbers =[1,2,3,4,]
Element= ["ElementA","ElementB","ElementC","ElementD"]
for e, n in zip(Element, Numbers):
    e+ ' = ' +n   #this part is wrong

What i want is a result like this in the end:

print ElementA
>1
print ElementB
>2
print ElementC
>3
print ElementD
>4

So what im trying to do is to fill up variables created from one list (Element) with values from another list (Numbers) in a kind of loop style. Does anyone know how to archive something like that? It should also be possible to assign many values contained in a list/array to variables.

O.k. if making something like that is unusual in python, so how do I load different data/values dynamically into python. Lets say I have a list of files and want to load all those files into python under their corresponding file names? Well Im more into R so Im not that into the python way of thinking yet. — Deset, Aug 28 '15 at 09:21
Something like that. In my very concrete case Im using `laspy` to open/connect a .las file in/to python. Well i can read out which information is available (and i want to save all that information to the corresponding variables). Then if i write `Xcoordinate = mydataname.X` i can save `all X values` in the variable `Xcoordinate`. And i want to do that for all the available information (X, Y, Z, classification etc.) not having to read the information out manually and type that code 8 times. Always just changing the variable name and the part behind the point `mydataname.(X,Y,Z etc)` — Deset, Aug 29 '15 at 11:54

score 1 · Answer 1 · answered Aug 27 '15 at 23:13

Do not do that.

You're already working with lists, so just create a list instead of hacking some hard-coded names. You could use a dictionary if you really wanted to use identifiers like A, B, etc., but you'd have a problem with more than 26 items, and you're just using it to make a sequence anyway. Integers are great for that, and of course we'll start at 0 because that's how it works.

>>> numbers = [1, 2, 3, 4]
>>> elements = [item for item in numbers]
>>> elements[0]
1

And at this point we can see that, for this example at least, you already had what you were looking for this whole time, in numbers.

>>> numbers = [1, 2, 3, 4]
>>> numbers[0]
1

Perfect.

score 0 · Answer 2 · answered Aug 27 '15 at 23:12

You may use exec but this is generally the wrong way to go.

for e, n in zip(Element, Numbers):
    exec(e + ' = ' + n)

You better should use a dictionnary:

my_dict = {}
for e, n in zip(Element, Numbers):
    my_dict[e] = n

Even simpler:

my_dict = dict(zip(Element, Numbers))

Python: Assaign values to variables using two lists

2 Answers2