Quiz: This code, designed to build a list of lists, with the inner lists being rows of data, is wrong because _____________________

f = open("in.txt")
data = []
for line in f:
    parsed_line = str.split(line,",")
    data_line = []
    for word in parsed_line:
        data_line.append(float(word))
        data.append(data_line)
print(data)
f.close()


1. of nothing, it's fine.
2. print(data) should be after the file is closed.
3. the data.append(data_line) isn't indented properly.

Correct! Because the data.append(data_line) is double indented, it gets done for every number in the file. As data_line is a list, rather than a number, you end up with a lists of lists in which each inner list is a single figure. What we're after is a list of lists where each inner lists is a row of numbers. We need to dedent the append one level so it is done for each row.

Quiz: The following JSON is broken because of ________________________________________

{
"type": "FeatureCollection",
"features": [     {
        "type": "Feature",
        "geometry":
        {
            "type": "Point",
            "coordinates": [42.0, 21.0]
        ,
        "properties":
        {
            "prop0": "value0"
        }
    } ]
}

1. an extra comma.
2. a missing data element.
3. a missing }.

Correct! The correct JSON is:
{
"type": "FeatureCollection",
"features": [     {
        "type": "Feature",
        "geometry":
        {
            "type": "Point",
            "coordinates": [42.0, 21.0]
        },
        "properties":
        {
            "prop0": "value0"
        }
    } ]
}
But you have to be pretty eagle eyed to stop these kind of syntax errors manually, which is why Python provides the command line json.tool for checking JSON files.