Python CSV To JSON Converter (Each column in one array)

csv2jsonOnPy.py

from collections import defaultdict
import csv
import json

def csv_to_json(csvFilePath, jsonFilePath):
    # Make Dictionary with default "List"
    jsonArray = defaultdict(list)
      
    #read csv file
    with open(csvFilePath, encoding='utf-8') as csvf: 
        # load csv file data using csv library's dictionary reader
        csvReader = csv.DictReader(csvf) 
        
        # convert each csv row into python dict
        for row in csvReader:
            for i in range(len(row)):
                jsonArray[list(row.keys())[i]].append(list(row.values())[i])
  
    # convert python jsonArray to JSON String and write to file
    with open(jsonFilePath, 'w', encoding='utf-8') as jsonf: 
        jsonString = json.dumps(jsonArray, indent=4)
        jsonf.write(jsonString)

# Test
csvFilePath = r'data.csv'
jsonFilePath = r'data.json'
csv_to_json(csvFilePath, jsonFilePath)