Building a dictionary from 2 given lists in python

Question

I want to build a script getting 2 lists (same size) from the user, L1 and L2, and build a dictionary: each object from L1 is a key, and each object from L2 is the value (for same index)

I'm trying to make a combined list first, in order to use the dict() function.

here is my script. It runs, but prints nothing. I want to print just to make sure I get build the right list to apply the dict() function to...

    print 'enter 2 lists with same len:'

L1=input('enter first list:')
L2=input('enter second list:')

if len(L1)==len(L2) and isinstance(L1,list) and isinstance(L2, list):
    D_list=[]
    D_ij=[]
    for i in L1:
        if isinstance (i,(int, str)):
            for j in L2:
                if isinstance(j, (tuple, list)):

                    for i in L1:
                        for j in L2:



                            D_ij=[L1[i], L2[j]]
                            D_list.extend([D_ij])

                            print D_list

else: print 'error'

You also need to make sure the list1 items are hashable – Padraic Cunningham Dec 22 '15 at 11:45 — Padraic Cunningham, Dec 22 '15 at 11:45

score 4 · Answer 1 · answered Dec 22 '15 at 11:26

4

You need zip function:

https://docs.python.org/2/library/functions.html#zip

You can build dictionary like this:

my_dict = dict(zip(list_1, list_2))

answered Dec 22 '15 at 11:26

Eugene Soldatov

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Iron Fist · Answer 2 · 2015-12-22T11:29:51.420

1

You can do it with dictionary comprehension:

d = {k:v for k,v in zip(L1,L2)}

edited Dec 22 '15 at 11:29

answered Dec 22 '15 at 11:27

Iron Fist

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this returns a set dude, no even a dict – Netwave Dec 22 '15 at 11:28
my bad...confused syntax .. :P – Iron Fist Dec 22 '15 at 11:30
1

May the down voter BE GENEROUS and spare his time to explain what's the reason behind his DOWN VOTE !! – Iron Fist Dec 22 '15 at 11:45

Building a dictionary from 2 given lists in python

2 Answers2