Combining two lists into a dictionary in python [duplicate]

Answer 1

 >>> listA = [1, 2, 3, 4, 5]
 >>> listB = ["red", "blue", "orange", "black", "grey"]
 >>> dict(zip(listA, listB))
 {1: 'red', 2: 'blue', 3: 'orange', 4: 'black', 5: 'grey'}

Answer 2

If you can't use zip, do a for loop.

d = {} #Dictionary

listA = [1, 2, 3, 4, 5]
listB = ["red", "blue", "orange", "black", "grey"]

for index in range(min(len(listA),len(listB))):
    # for index number in the length of smallest list
    d[listA[index]] = listB[index]
    # add the value of listA at that place to the dictionary with value of listB

print (d) #Not sure of your Python version, so I've put d in parentheses

Answer 3

I suspect your teacher wants you to write something like

for i in range(len(listA)):
    print listA[i], listB[i]

However this is an abomination in Python.

Here is one way without using zip

>>> listA = [1, 2, 3, 4, 5]
>>> listB = ["red", "blue", "orange", "black", "grey"]
>>> 
>>> b_iter = iter(listB)
>>> 
>>> for item in listA:
...     print item, next(b_iter)
... 
1 red
2 blue
3 orange
4 black
5 grey

However zip is the natural way to solve this, and your teacher should be teaching you to think that way

Answer 4

Special Teacher edition:

list_a = [1, 2, 3, 4, 5]
list_b = ["red", "blue", "orange", "black", "grey"]

for i in range(min(len(list_a), len(list_b))):
    print list_a[i], list_b[i]

Answer 5

Usually, zip is the best way to solve your problem. But as it is a homework, and your teacher does not allow you to use zip, I think you can take any solution from this page.

And I provide a version of using a lambda function. Note that if the length of both lists are not identical, a None will be printed at the corresponding place.

>>> list_a = [1, 2, 3, 4, 5]
>>> list_b = ["red", "blue", "orange", "black", "grey"]
>>> for a,b in map(lambda a,b : (a,b), list_a, list_b):
...     print a,b
... 
1 red
2 blue
3 orange
4 black
5 grey