Given a list of dictionaries like:

[{'first name': 'John', 'last name': 'Smith', 'age': 20, 'sport': 'basketball', 'level': 'college', 'team': 'Bruins', 'team city': 'Los Angeles'}, {'first name': 'Wayne', 'last name': 'Gretsky', 'age': 29, 'sport': 'ice hockey', 'level': 'professional', 'team': 'Kings', 'team city': 'Los Angeles'}, {'first name': 'Dan', 'last name': 'Marino', 'age': 31, 'sport': 'football', 'level': 'professional', 'team': 'Dolphins', 'team city': 'Miami'}...]

Outside of using a SQL query via sqllite module, what would be the best approach of writing a script that returns a smaller list of dictionaries for a different combination of filters (ex. all players with last name of 'Smith', all players under the age of 25, all players with the last name 'Smith' who are under the age of 25, all players in professional teams in Las Vegas, all college baseball players under the age of 21 who are not from Los Angeles, etc.)?

I'm not so much asking for specific code, but what would be your thought process in structuring clean code for such a script?

So let's say I have a dictionary of

dict = { chevy_01 : "Ford", chevy_02: "Tahoe"}

I want to filter through the KEYS of the dict and get the last two characters of the keys while later performing another function. So I imagine something like this

{for keys in vals print (key[-2:]} 

But I want the end of the function to return a list of the last two characters in the dict so it will just return [01, 02].

I want to do this in a lambda function I'm bad at dict comprehension. Can someone help me out?

I have a nested dictionary of source words, target words, and their frequency counts. It looks like this:

src_tgt_dict = {"each":{"chaque":3}, "in-front-of":{"devant":4}, "next-to":{"à-côté-de":5}, "for":{"pour":7}, "cauliflower":{"chou-fleur":4}, "on":{"sur":2, "panda-et":2}}

I am trying to filter the dictionary so that only key-value pairs that are prepositions remain. To that end, I've written the following:

tgt_preps = set(["devant", "pour", "sur", "à"]) #set of target prepositions

src_tgt_dict = {"each":{"chaque":3}, "in-front-of":{"devant":4}, "next-to":{"à-côté-de":5}, "for":{"pour":7}, "cauliflower":{"chou-fleur":4}, "on":{"sur":2, "panda-et":2}}

new_tgt_preps = [] #list of new target prepositions

for src, d in src_tgt_dict.items(): #loop into the dictionary
    for tgt, count in d.items(): #loop into the nested dictionary
        check_prep = []
        if "-" in tgt: #check to see if hyphen occurs in the target word (this is to capture multi-word prepositions that are not in the original preposition set)
            check_prep.append(tgt[0:(tgt.index("-"))]) #if there's a hyphen, append the preceding word to the check_prep list
            for t in check_prep: 
                if t in tgt_preps: # check to see if the token preceding the hyphen is a preposition
                    new_tgt_preps.append(tgt) #if yes, append the multi-word preposition to the list of new target prepositions

tgt_preps.update(new_tgt_preps) # update the set of prepositions to include the multi-word prepositions

temp_2_src_tgt_dict = {} # create new dict for filtering
for src, d in src_tgt_dict.items(): # loop into the dictionary
    for tgt, count in d.items(): # loop into the nested dictionary
        if tgt in tgt_preps: # if the target is in the set of target prepositions
            temp_2_src_tgt_dict[tgt] = count # add to the new dict with the tgt as the key and the count as the value

When I print the new dict, I get the following:

{'devant': 4, 'pour': 7, 'sur': 2, 'à-côté-de': 5}

And it totally makes sense why I get that, because that's what I told the machine to do. But that's not my intention!

What I want is:

{"in-front-of:{"devant":4}, "for":{"pour":7}, "on":{"sur":2}, {"next-to":{"à-côté-de":5}}

I've tried to instantiate the nested dictionary by writing:

temp_2_src_tgt_dict[tgt][src] = count

but that throws up a Key Error.

Can anyone provide any suggestions or advice? Thank you in advance for your help.