Caching error

🎈 Using Streamlit
1

I am trying to cache a function and I’m getting an error that is pointing towards these lines of code:

result = [[geopy.distance.geodesic(coords1, coords2).km for coords1 in list2] for coords2 in list1]

filtered_inside_radius = [[1 if y <= radius and y > 0 else 0 for y in x] for x in result]

The code calculates the distance between points in two lists and then filters the results based on “radius” which is a streamlit slider.

I don’t see anything that would obviously be causing an error. Any thoughts?

2

Still stuck on this. The more precise error that is being generated is:

UserHashError: 'coords2'

I’ve since learned that lists are not hashable so I’ve converted them to the variables to tuples but it is still not working:

    result = tuple([[geopy.distance.geodesic(coords1, coords2).km for coords1 in list2] for coords2 in 
    list1])

    filtered_inside_radius = tuple([[1 if y <= radius and y > 0 else 0 for y in x] for x in result])
3

Okay I figured it out. But what I don’t understand is why it works. Changing the code to the below allowed me to successfully cache:

result = []

for coords2 in list1:
   results2 = [] 
   for coords1 in list2:
       distance = geopy.distance.geodesic(coords1,coords2).km
       results2.append(distance)
   result.append(results2)    

result = list([[geopy.distance.geodesic(coords1, coords2).km for coords1 in list2] for coords2 in list1])


filtered_inside_radius = []
    
for x in result:
    results4 = [] 
    for y in x:
        if y <= radius and y > 0:
            y = 1
            results4.append(y)
        else:
            y = 0
            results4.append(y)
    filtered_inside_radius.append(results4)

Can anyone explain why this is the case?