Python - convert csv file to JSON

Question

I need to convert a csv file into a hierarchical JSON object (preferably using Python). I thought that the script I have (below) does a correct job of converting to JSON, but the JavaScript library I'm feeding the JSON data to (D3.js) doesn't work with it.

The csv file looks like this:

subject,branch,book,chapter,Encode ID,Level 1,Level 2,Level 3,Level 4
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.000,Right Triangles and an Introduction to Trigonometry,,,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.004,,The Pythagorean Theorem,,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.005,,,The Pythagorean Theorem,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.006,,,Pythagorean Triples,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.007,,,Converse of the Pythagorean Theorem,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.008,,,The Distance Formula,
MAT,TRI,CK-12 Trigonometry - Second Edition,Right Triangles and an Introduction to Trigonometry,MAT.TRI.009,,Special Right Triangles,,

Right now, I have the following code the recursively builds the hierarchical array:

import csv
import json
import random

random.seed()

# open up the csv file
f = open('/path/to/file','rU')
c = csv.DictReader(f)

# lists for keeping track of what subjects and branches I've already iterated over
subject_list = []
branch_list = []
lev1_list = []
lev2_list = []
lev3_list = []
lev4_list = []

# iterate through file
i = 0
for row in c:
    if i == 0:
        subject = row['subject']
        branch = row['branch']
        if len(row['Level 1']) > 0:
            lev1 = row['Level 1']
        else:
            lev2 = None
        if len(row['Level 2']) > 0:
            lev2 = row['Level 2']
        else:
            lev2 = None
        if len(row['Level 3']) > 0:
            lev3 = row['Level 3']
        else:
            lev3 = None

    else:
        if row['subject'] != subject:

            # add all branches to this subject
            subject_list.append({'name':subject,'type':'subject','children':branch_list})


            # set current subject
            subject = row['subject']

        if row['branch'] != branch:
            # add all concepts to this branch
            branch_list.append({'name':branch,'type':'branch','children':lev1_list})

            # empty lev1_list
            lev1_list = []

            # set new branch
            branch = row['branch']

        if len(row['Level 1']) > 0 and row['Level 1'] != lev1:
            # print lev1
            # add all level 2 concepts to this level 1
            lev1_list.append({'name':lev1,'type':'concept','level':1,'children':lev2_list})
            #print lev1
            #empty lev2_list
            lev2_list = []

            #lev1_list.append(row['Level 1'])
            lev1 = row['Level 1']

        if len(row['Level 2']) > 0 and row['Level 2'] != lev3:
            #print lev2
            #print lev3_list
            # add all level 3 concepts to this level 2
            if lev2 is not None:
                lev2_list.append({'name':lev2,'type':'concept','level':2,'children':lev3_list})

            # empty lev3_list
            lev3_list = []

            # lev2_list.append(row['Level 2'])
            lev2 = row['Level 2']

        if len(row['Level 3']) > 0 and row['Level 3'] != lev3:
            # print lev3
            # add all level 4 concepts to this level 4
            # lev3_list.append({'name':lev3,'type':'concept','level':3})

            # empty level 4 concepts
            # lev4_list = []

            # add new level 3
            if lev3 is not None:
                lev3_list.append({'name':lev3,'type':'concept','level':3,'size':random.randint(1,100)})
            lev3 = row['Level 3']


        #if row['Level 4'] is not None and row['Level 4'] is not lev4:
        #   lev4_list.append({'name':lev4,'type':'concept','level':4})
        #   lev4 = row['Level 4']

    i += 1

f.close()


branch_list.append({'name':branch,'type':'branch','children':lev1_list})

#subject_list.append({'name':subject,'type':'subject','children':branch_list})
subject_dict = {'name':subject,'type':'subject','children':branch_list}

#json_list= json.dumps(subject_list)
json_list = json.dumps(subject_dict)

f = open('/Users/thaymore/Sites/d3/data/trig_map.json','wb')
f.write(json_list)
f.close()

What this gets me right now is something like this:

{"type": "subject", "name": "MAT", "children": [{"type": "branch", "name": "TRI", "children": [{"children": [{"children": [{"size": 40, "type": "concept", "name": "The Pythagorean Theorem", "level": 3}, {"size": 19, "type": "concept", "name": "Pythagorean Triples", "level": 3}, {"size": 68, "type": "concept", "name": "Converse of the Pythagorean Theorem", "level": 3}], "type": "concept", "name": "The Pythagorean Theorem", "level": 2}, {"children": [{"size": 28, "type": "concept", "name": "The Distance Formula", "level": 3}, {"size": 49, "type": "concept", "name": "Special Right Triangle #1: Isosceles Right Triangle", "level": 3}, {"size": 33, "type": "concept", "name": "Special Right Triangle #2: 30-60-90 Triangle", "level": 3}], "type": "concept", "name": "Special Right Triangles", "level": 2}, {"children": [{"size": 18, "type": "concept", "name": "Using Special Right Triangle Ratios", "level": 3}, {"size": 49, "type": "concept", "name": "The Sine, Cosine, and Tangent Functions", "level": 3}], "type": "concept", "name": "Basic Trigonometric Functions", "level": 2}, {"children": [{"size": 100, "type": "concept", "name": "Secant, Cosecant, and Cotangent Functions", "level": 3}, {"size": 73, "type": "concept", "name": "Solving Right Triangles", "level": 3}, {"size": 93, "type": "concept", "name": "Inverse Trigonometric Functions", "level": 3}, {"size": 88, "type": "concept", "name": "Finding the Area of a Triangle", "level": 3}, {"size": 6, "type": "concept", "name": "Angles of Elevation and Depression", "level": 3}, {"size": 3, "type": "concept", "name": "Right Triangles and Bearings", "level": 3}], "type": "concept", "name": "Solving Right Triangles", "level": 2}, {"children": [{"size": 68, "type": "concept", "name": "Other Applications of Right Triangles", "level": 3}, {"size": 92, "type": "concept", "name": "Angles of Rotation in Standard Position", "level": 3}], "type": "concept", "name": "Measuring Rotation", "level": 2}, {"children": [{"size": 14, "type": "concept", "name": "Coterminal Angles", "level": 3}, {"size": 68, "type": "concept", "name": "Trigonometric Functions of Angles in Standard Position", "level": 3}], "type": "concept", "name": "Applying Trig Functions to Angles of Rotation", "level": 2}, {"children": [{"size": 61, "type": "concept", "name": "The Unit Circle", "level": 3}, {"size": 95, "type": "concept", "name": "Reference Angles and Angles in the Unit Circle", "level": 3}, {"size": 11, "type": "concept", "name": "Trigonometric Functions of Negative Angles", "level": 3}, {"size": 45, "type": "concept", "name": "Trigonometric Functions of Angles Greater than 360 Degrees", "level": 3}], "type": "concept", "name": "Trigonometric Functions of Any Angle", "level": 2}], "type": "concept", "name": "Right Triangles and an Introduction to Trigonometry", "level": 1}, {"children": [{"children": [{"size": 20, "type": "concept", "name": "Using a Calculator to Find Values", "level": 3}, {"size": 25, "type": "concept", "name": "Reciprocal identities", "level": 3}, {"size": 40, "type": "concept", "name": "Domain, Range, and Signs of Trig Functions", "level": 3}, {"size": 97, "type": "concept", "name": "Quotient Identities", "level": 3}, {"size": 18, "type": "concept", "name": "Cofunction Identities and Reflection", "level": 3}], "type": "concept", "name": "Relating Trigonometric Functions", "level": 2}, {"children": [{"size": 35, "type": "concept", "name": "Pythagorean Identities", "level": 3}, {"size": 95, "type": "concept", "name": "Understanding Radian Measure", "level": 3}, {"size": 30, "type": "concept", "name": "Critial Angles in Radians", "level": 3}, {"size": 16, "type": "concept", "name": "Converting Any Degree to Radians", "level": 3}, {"size": 25, "type": "concept", "name": "The Six Trig Functions and Radians", "level": 3}], "type": "concept", "name": "Radian Measure", "level": 2}, {"children": [{"size": 19, "type": "concept", "name": "Check the Mode", "level": 3}, {"size": 63, "type": "concept", "name": "Rotations", "level": 3}, {"size": 33, "type": "concept", "name": "Length of Arc", "level": 3}, {"size": 54, "type": "concept", "name": "Area of a Sector", "level": 3}, {"size": 6, "type": "concept", "name": "Length of a Chord", "level": 3}], "type": "concept", "name": "Applications of Radian Measure", "level": 2}, {"children": [{"size": 71, "type": "concept", "name": "Angular Velocity", "level": 3}, {"size": 16, "type": "concept", "name": "The Sine Graph", "level": 3}, {"size": 65, "type": "concept", "name": "The Cosine Graph", "level": 3}, {"size": 32, "type": "concept", "name": "The Tangent Graph", "level": 3}, {"size": 93, "type": "concept", "name": "The Three Reciprocal Functions", "level": 3}, {"size": 30, "type": "concept", "name": "Cotangent", "level": 3}, {"size": 4, "type": "concept", "name": "Cosecant", "level": 3}], "type": "concept", "name": "Circular Functions of Real Numbers", "level": 2}, {"children": [{"size": 100, "type": "concept", "name": "Secant", "level": 3}, {"size": 40, "type": "concept", "name": "Vertical Translations", "level": 3}], "type": "concept", "name": "Translating Sine and Cosine Functions", "level": 2}, {"children": [{"size": 58, "type": "concept", "name": "Horizontal Translations or Phase Shifts", "level": 3}, {"size": 76, "type": "concept", "name": "Amplitude", "level": 3}, {"size": 91, "type": "concept", "name": "Period and Frequency", "level": 3}], "type": "concept", "name": "Amplitude, Period and Frequency", "level": 2}, {"children": [{"size": 78, "type": "concept", "name": "Combining Amplitude and Period", "level": 3}, {"size": 12, "type": "concept", "name": "The Generalized Equations", "level": 3}, {"size": 22, "type": "concept", "name": "Drawing Sketches/Identifying Transformations from the Equation", "level": 3}], "type": "concept", "name": "General Sinusoidal Graphs", "level": 2}], "type": "concept", "name": "Graphing Trigonometric Functions - 2nd edition", "level": 1}, {"children": [{"children": [{"size": 81, "type": "concept", "name": "Writing the Equation from a Sketch", "level": 3}, {"size": 60, "type": "concept", "name": "Tangent and Cotangent", "level": 3}, {"size": 27, "type": "concept", "name": "Secant and Cosecant", "level": 3}], "type": "concept", "name": "Graphing Tangent, Cotangent, Secant, and Cosecant", "level": 2}, {"children": [{"size": 62, "type": "concept", "name": "Graphing Calculator Note", "level": 3}, {"size": 20, "type": "concept", "name": "Quotient Identity", "level": 3}, {"size": 15, "type": "concept", "name": "Reciprocal Identities", "level": 3}, {"size": 28, "type": "concept", "name": "Pythagorean Identity", "level": 3}, {"size": 28, "type": "concept", "name": "Even and Odd Identities", "level": 3}], "type": "concept", "name": "Fundamental Identities", "level": 2}, {"children": [{"size": 24, "type": "concept", "name": "Cofunction Identities", "level": 3}, {"size": 91, "type": "concept", "name": "Working with Trigonometric Identities", "level": 3}], "type": "concept", "name": "Proving Identities", "level": 2}, {"children": [{"size": 59, "type": "concept", "name": "Technology Note", "level": 3}, {"size": 26, "type": "concept", "name": "Simplifying Trigonometric Expressions", "level": 3}, {"size": 94, "type": "concept", "name": "Solving Trigonometric Equations", "level": 3}, {"size": 49, "type": "concept", "name": "Solving Trigonometric Equations Using Factoring", "level": 3}], "type": "concept", "name": "Solving Trigonometric Equations", "level": 2}, {"children": [{"size": 25, "type": "concept", "name": "Solving Trigonometric Equations Using the Quadratic Formula", "level": 3}, {"size": 11, "type": "concept", "name": "Sum and Difference Formulas: cosine", "level": 3}, {"size": 30, "type": "concept", "name": "Using the Sum and Difference Identities of cosine", "level": 3}, {"size": 75, "type": "concept", "name": "Sum and Difference Identities: sine", "level": 3}, {"size": 94, "type": "concept", "name": "Sum and Difference Identities: Tangent", "level": 3}, {"size": 22, "type": "concept", "name": "Using the Sum and Difference Identities to Verify Other Identities", "level": 3}], "type": "concept", "name": "Sum and Difference Identities", "level": 2}, {"children": [{"size": 15, "type": "concept", "name": "Solving Equations with the Sum and Difference Formulas", "level": 3}, {"size": 88, "type": "concept", "name": "Deriving the Double Angle Identities", "level": 3}, {"size": 42, "type": "concept", "name": "Applying the Double Angle Identities", "level": 3}], "type": "concept", "name": "Double Angle Identities", "level": 2}, {"children": [{"size": 13, "type": "concept", "name": "Solving Equations with Double Angle Identities", "level": 3}, {"size": 36, "type": "concept", "name": "Deriving the Half Angle Formulas", "level": 3}], "type": "concept", "name": "Half-Angle Identities", "level": 2}], "type": "concept", "name": "Trigonometric Identities and Equations - 2nd edition", "level": 1}, {"children": [{"children": [{"size": 100, "type": "concept", "name": "Solving Trigonometric Equations Using Half Angle Formulas", "level": 3}, {"size": 93, "type": "concept", "name": "Sum to Product Formulas for Sine and Cosine", "level": 3}, {"size": 71, "type": "concept", "name": "Product to Sum Formulas for Sine and Cosine", "level": 3}, {"size": 53, "type": "concept", "name": "Solving Equations with Product and Sum Formulas", "level": 3}, {"size": 45, "type": "concept", "name": "Triple-Angle Formulas and Beyond", "level": 3}, {"size": 18, "type": "concept", "name": "Linear Combinations", "level": 3}], "type": "concept", "name": "Products, Sums, Linear Combinations, and Applications", "level": 2}, {"children": [{"size": 73, "type": "concept", "name": "Applications & Technology", "level": 3}, {"size": 54, "type": "concept", "name": "Defining the Inverse of the Trigonometric Ratios", "level": 3}, {"size": 15, "type": "concept", "name": "Exact Values for Inverse Sine, Cosine, and Tangent", "level": 3}], "type": "concept", "name": "Basic Inverse Trigonometric Functions", "level": 2}, {"children": [{"size": 1, "type": "concept", "name": "Finding Inverses Algebraically", "level": 3}, {"size": 93, "type": "concept", "name": "Finding the Inverse by Mapping", "level": 3}], "type": "concept", "name": "Graphing Inverse Trigonometric Functions", "level": 2}, {"children": [{"size": 79, "type": "concept", "name": "Finding the Inverse of the Trigonometric Functions", "level": 3}, {"size": 29, "type": "concept", "name": "Composing Trig Functions and their Inverses", "level": 3}, {"size": 19, "type": "concept", "name": "Composing Trigonometric Functions", "level": 3}, {"size": 53, "type": "concept", "name": "Inverse Reciprocal Functions", "level": 3}, {"size": 28, "type": "concept", "name": "Composing Inverse Reciprocal Trig Functions", "level": 3}], "type": "concept", "name": "Inverse Trigonometric Properties", "level": 2}], "type": "concept", "name": "Inverse Trigonometric Functions - 2nd edition", "level": 1}, {"children": [{"children": [], "type": "concept", "name": "Applications & Models", "level": 2}, {"children": [{"size": 42, "type": "concept", "name": "Trigonometry in Terms of Algebra", "level": 3}, {"size": 38, "type": "concept", "name": "Derive the Law of Cosines", "level": 3}, {"size": 82, "type": "concept", "name": "Case #1:  Finding the Side of an Oblique Triangle", "level": 3}, {"size": 68, "type": "concept", "name": "Case #2:  Finding any Angle of a Triangle", "level": 3}], "type": "concept", "name": "The Law of Cosines", "level": 2}, {"children": [{"size": 20, "type": "concept", "name": "Identify Accurate Drawings of General Triangles", "level": 3}, {"size": 90, "type": "concept", "name": "Find the Area Using Three Sides:  Heron\u2019s Formula", "level": 3}, {"size": 7, "type": "concept", "name": "Heron\u2019s Formula:", "level": 3}], "type": "concept", "name": "Area of a Triangle", "level": 2}, {"children": [{"size": 21, "type": "concept", "name": "Finding a Part of the Triangle, Given the Area", "level": 3}, {"size": 58, "type": "concept", "name": "Deriving the Law of Sines", "level": 3}, {"size": 15, "type": "concept", "name": "AAS (Angle-Angle-Side)", "level": 3}, {"size": 41, "type": "concept", "name": "ASA (Angle-Side-Angle)", "level": 3}], "type": "concept", "name": "The Law of Sines", "level": 2}, {"children": [{"size": 87, "type": "concept", "name": "Solving Triangles", "level": 3}, {"size": 31, "type": "concept", "name": "Possible Triangles with SSA", "level": 3}, {"size": 45, "type": "concept", "name": "Using the Law of Sines", "level": 3}], "type": "concept", "name": "The Ambiguous Case", "level": 2}, {"children": [{"size": 40, "type": "concept", "name": "Using the Law of Cosines", "level": 3}, {"size": 2, "type": "concept", "name": "Summary of Triangle Techniques", "level": 3}, {"size": 18, "type": "concept", "name": "Using the Law of Cosines", "level": 3}], "type": "concept", "name": "General Solutions of Triangles", "level": 2}, {"children": [{"size": 42, "type": "concept", "name": "Using the Law of Sines", "level": 3}, {"size": 6, "type": "concept", "name": "Directed Line Segments, Equal Vectors, and Absolute Value", "level": 3}, {"size": 60, "type": "concept", "name": "Vector Addition", "level": 3}, {"size": 76, "type": "concept", "name": "Vector Subtraction", "level": 3}], "type": "concept", "name": "Vectors", "level": 2}], "type": "concept", "name": "Triangles and Vectors", "level": 1}]}]}

I think this might technically fit the JSON specs, but the library that I'm trying to feed the JSON data to (D3.js) can't seem to do anything with it. Is it because the order of the elements is out-of-whack (i.e., the "children" element is coming before the "name" element)? Is it something more basic that I'm doing?

(The file whose structure I'm trying to match is located here.)

Answer 1

Wouldn't this work?

import json

f = open('path/to/file','r')

arr=[]
headers = []

for header in f.readline().split(','):
  headers.append(header)

for line in f.readlines():
  lineItems = {}
  for i,item in enumerate(line.split(',')):  
    lineItems[headers[i]] = item
  arr.append(lineItems)

f.close()

jsonText = json.dumps(arr)

print jsonText