# Learn Algorithm Design by Building a Shortest Path Algorithm - Step 29

### Tell us what’s happening:

I get the error that I should have a paths variable- I do.

I believe my error is with what I put inside the variable. But not exactly sure as I don’t get an error regarding that.

``````my_graph = {
'A': [('B', 3), ('D', 1)],
'B': [('A', 3), ('C', 4)],
'C': [('B', 4), ('D', 7)],
'D': [('A', 1), ('C', 7)]
}

/* User Editable Region */

def shortest_path(graph, start):
unvisited = list(graph)
distances = {}
paths = {key:[] in graph.items}

print(f'Unvisited: {unvisited}\nDistances: {distances}')

shortest_path(my_graph, 'A')

/* User Editable Region */

``````

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36`

### Challenge Information:

Learn Algorithm Design by Building a Shortest Path Algorithm - Step 29

1 Like

On the right track but you are definitely missing important items in your dict comprehension. Remember doing list comprehensions, it’s similar. You need “FOR” and “IN” there, just like a `for` loop. This is the essential structure of a comprehension. Check the example again:

`{key: val **for** key **in** dict}`

This will copy all the keys and values from dict. All you want is the keys, instead of the val you just want an empty list.

`paths = {key:[] `

You got it, looks good. Back to the example:

`for key in dict}`

Copy that, but your dictionary is called `graph`

`in graph.items}`

Almost good! Why did you decide to add items to the end?

4 Likes

I added graph items because I overcomplicated the instructions (assign EVERY item from graph).