For a, b in c, d Python

Question

I have a list of keys and a list of values, I want to fill a dictionary so like:

 for key, value in listKeys, listValues:
     dict[key] = value

However, I get the following error:

builtins.ValueError: too many values to unpack (expected 2)

Answer 1

You want the zip function to make a generator of tuples of values from each of a number of inputs:

mydict = {}
for key, value in zip(listKeys, listValues):
     mydict[key] = value

That said, you could skip the rigmarole of writing your own loop and let the dict constructor do the work; it can take an iterable of key/value pairs to initialize itself, and avoid the Python level loop entirely:

mydict = dict(zip(listKeys, listValues))

or if mydict is an existing non-empty dict, use the update method, which accepts the same arguments as the constructor:

mydict.update(zip(listKeys, listValues))

Side-note: I renamed your variable to mydict, because shadowing built-in names like dict is a terrible, terrible idea.

Answer 2

Iterate through two lists simultaneously using zip :

for key, value in zip(listKeys, listValues) :
    dict[key] = value

Answer 3

Use zip:

for key, value in zip(listKeys, listValues): dict[key] = value