Check list for part of value and return whole value

I have a master list of ID numbers and another list of partial ID numbers. I need to check if the partial ID number is in the master list. If so, I need to return the whole ID number into a new list. What I have:

master_list = ['20000-K-A', '20000-K-B', '20000-K-C', '30000-R-X', '30000-R-V', '30000-R-F']

partial_list = [20000, 40000, 500000]

new_list =[]

for x in partial_list:
  if x in master_list:
    new_list.append(x)

print(new_list)

Now this only works if the partial ID number is EXACTLY what is in the master list. How do I return the value from the master list so that I can add it to the new list?

>Solution :

One option is to create a lookup dictionary first from master_list (note that the master_list is a list of strings while partial_list is a list of integers, so we need to cast the prefix to int):

d = {}
for item in master_list:
    k, _ = item.split('-', maxsplit=1)
    d.setdefault(int(k), []).append(item)

which looks like:

{20000: ['20000-K-A', '20000-K-B', '20000-K-C'], 
 30000: ['30000-R-X', '30000-R-V', '30000-R-F']}

Then iterate over partial_list to get the partially matching Ids:

new_list =[]
for x in partial_list:
    new_list.extend(d.get(x, []))

Output:

['20000-K-A', '20000-K-B', '20000-K-C']