Python function 将文本文件读入字典

Question

I have a text file that contain the following lines:

103;1;2

103;6;2

Where the first item is the participant no., the second item is the lesson followed and the third item is the rate.

I want to combine the ratings of certain lessons in a dictionary.

This dictionary should have the participant number as key and a list of ratings belonging to that participant as value. There are 7 lessons in total. If the lesson is not taken, the rating in the list should be "NA".

So for the text file above, the function should return a dictionary as follows:

{'103': [2.0, 'NA', 'NA', 'NA', 'NA', 2.0, 'NA']}

How do I need to do this?

I have made a function that splits the items the way I want and creates a dictionary with the right key:

def ratings():

    dictionary = {}
    file = open("ratings.csv")
    for line in file:
        line = line.split(";")
        dictionary[line[0]] = []
    return dictionary

This code returns my dictionary as follows:

{'103': []}

However, I do struggle with the value part of the dictionary I need to return, ie the list with ratings of each participant. How can I combine the ratings in one list and insert "NA" if there is a missing value.

Answer 1

The problem is here:

dictionary[line[0]] = []

You're telling Python that the value in that dictionary for the key 103 is [] which is empty.

You probably want something like:

def ratings():
    dictionary = {}
    file = open("ratings.csv")
    for line in file:
        line = line.split(";")
        if line[0] in dictionary: # already have some data for the participant
            dictionary[line[0]][line[1] - 1] = line[2] # minus 1 because Python is zero-indexed
        else: # new participant
            dictionary[line[0]] = ['NA','NA','NA','NA','NA','NA','NA',]
            dictionary[line[0]][line[1] - 1] = line[2] # minus 1 because Python is zero-indexed
    return dictionary