3 dimensional dictionary

Question

subjects = {
    0:9,'fail': 0,
   9:14, 'pass': 25,
   15:17, 'merit': 40,
    18:20,'Distinction': 50
}

I want the dictionary above to contain 3 dimensions. user input will be between the initial numbers. depending what number the user enters the following message should be displayed. eg. 4 is a fail worth 0 points , 10 is a pass worth 25 points and so on.

inputs = ['irish','english','french','italian','dutch','german']
for i in range(1, 7):
    inputs.append(raw_input('Enter mark for {}: '.format(i)))

I want the loop to ask enter mark for irish etc

print sum(subjects[name][value] for name in inputs)

Can this be done?

Answer 1

A dictionary stores its values based on a hash of the keys.

This means a dictionary lookup only returns entries whose keys exactly match the one used in the lookup.

You cannot have a key be "any number in the range 3 to 5" and expect a lookup for "4" to hit.

However, what you can do is duplicate the dictionary entries:

subject_ranges = [(0, 8, 'fail', 0),
                  (9, 14, 'pass', 25),
                  (15, 17, 'merit', 40),
                  (18, 20, 'Distinction', 50)]
subjects = {}
for low, high, descr, points in subject_ranges:
   for score in range(low, high+1):
      subjects[score] = {'description': descr, 'value': points}

And collect the input like this:

input_names = ['irish','english','french','italian','dutch','german']
scores = []
for i in range(len(input_names)):
    scores.append(int(raw_input('Enter mark for %s: ' % input_names[i])))

Now this code will work to print the total score as you wished:

print sum(subjects[score]['value'] for score in scores)

This is not a "3-dimensional dictionary", nor anything like it. It's a dictionary whose keys are integers and whose values are two-element dictionaries (you could use NamedTuple if you wished). But from your question, it doesn't look like you actually needed anything more sophisticated than this.