You're looking for Python Dictionaries.

sample = {}
for i in range(6):
   # some code that gives you x
   sample[i] = x
print(sample)

Do note, however, that since your keys are just 0, 1, 2 etc., you may want to just use a list instead:

sample = []
for i in range(6):
    # some code that gives you x
    sample.append(x)
print(sample)

Note that dictionary access using sample[key] will look identical to list access using sample[index] since you're just using consecutive numeric keys.

In Python, dictionary keys are unique. If you assign a value to the same key again, it gets overwritten. Example :

dct = {}
dct["key"] = "value"
print(dct)
dct["key"] = "value2"
print(dct)

Output :

{"key": "value"}
{"key": "value2"}

The only option you have is to create a list of amounts and a list of ids:

new_debt_dic = {"amounts": [], "ids": []}
for i in debts_list:
    new_debt_dic["amounts"].append(i["amount"])
    new_debt_dic["ids"].append(i["id"])
print(new_debt_dic)

Output :

{"amounts": [123.46, 100, ...], "ids": [0, 1, ...]}

In your current code, what Dictionary.update() does is that it updates (update means the value is overwritten from the value for same key in passed in dictionary) the keys in current dictionary with the values from the dictionary passed in as the parameter to it (adding any new key:value pairs if existing) . A single flat dictionary does not satisfy your requirement , you either need a list of dictionaries or a dictionary with nested dictionaries.

If you want a list of dictionaries (where each element in the list would be a diciotnary of a entry) then you can make case_list as a list and then append case to it (instead of update) .

Example -

case_list = []
for entry in entries_list:
    case = {'key1': entry[0], 'key2': entry[1], 'key3':entry[2] }
    case_list.append(case)

Or you can also have a dictionary of dictionaries with the key of each element in the dictionary being entry1 or entry2 , etc and the value being the corresponding dictionary for that entry.

case_list = {}
for entry in entries_list:
    case = {'key1': value, 'key2': value, 'key3':value }
    case_list[entryname] = case  #you will need to come up with the logic to get the entryname.

You create a new key/value pair on a dictionary by assigning a value to that key

d = {'key': 'value'}
print(d)  # {'key': 'value'}

d['mynewkey'] = 'mynewvalue'

print(d)  # {'key': 'value', 'mynewkey': 'mynewvalue'}

If the key doesn't exist, it's added and points to that value. If it exists, the current value it points to is overwritten.