Python Value Error: not enough values to unpack

Question

Get the following error in code, unsure of what it means or what I did wrong. Just trying to initialize three list values to empty collections:

nba,nfl,mlb = []
         


        

Answer 1

The issue is , left hand side values are not enough to assign to the number of variable on the left so instead do

nba,nfl,mlb = [],[],[]

Answer 2

Another option if you want to unpack a generator for instance:

nba,nfl,mlb = [[] for _ in range(3)]

Answer 3

basically means left hand side has more values than right hand side of =

nba = nfl = mlb = [] should get you three list values initialized to empty collections. So should nba, nfl, mlb = [], [], []

Answer 4

This attempts to unpack, as the error message says, an iterable on the right hand side into three variables on the left hand side, so, for example, after running a,b,c = 1,2,3 you get a == 1 and b == 2 and c == 3.

In your case, this iterable is empty, so "there are not enough values to unpack": there are three variables, but no values in the iterable (the iterable is an empty list). What you need is the following:

a,b,c = [],[],[]

Here you have three variables a,b,c and the iterable discussed above is the tuple [],[],[] in this case.