json_to_csv_converter.py fixed for Python 3

[mattdee]

"""Convert the Yelp Dataset Challenge dataset from json format to csv.

For more information on the Yelp Dataset Challenge please visit http://yelp.com/dataset_challenge

"""
import argparse
import collections
import csv
import simplejson as json


def read_and_write_file(json_file_path, csv_file_path, column_names):
    """Read in the json dataset file and write it out to a csv file, given the column names."""
    with open(csv_file_path, 'w') as fout:
        csv_file = csv.writer(fout)
        csv_file.writerow(list(column_names))
        with open(json_file_path) as fin:
            for line in fin:
                line_contents = json.loads(line)
                #print(column_names, line_contents)
                csv_file.writerow(get_row(line_contents, column_names))

def get_superset_of_column_names_from_file(json_file_path):
    """Read in the json dataset file and return the superset of column names."""
    column_names = set()
    with open(json_file_path) as fin:
        for line in fin:
            line_contents = json.loads(line)
            column_names.update(
                    set(get_column_names(line_contents).keys())
                    )
    return column_names

def get_column_names(line_contents, parent_key=''):
    """Return a list of flattened key names given a dict.

    Example:

        line_contents = {
            'a': {
                'b': 2,
                'c': 3,
                },
        }

        will return: ['a.b', 'a.c']

    These will be the column names for the eventual csv file.

    """
    column_names = []
    for k, v in line_contents.items():
        column_name = "{0}.{1}".format(parent_key, k) if parent_key else k
        if isinstance(v, collections.MutableMapping):
            column_names.extend(
                    get_column_names(v, column_name).items()
                    )
        else:
            column_names.append((column_name, v))
    return dict(column_names)

def get_nested_value(d, key):
    """Return a dictionary item given a dictionary `d` and a flattened key from `get_column_names`.
    
    Example:

        d = {
            'a': {
                'b': 2,
                'c': 3,
                },
        }
        key = 'a.b'

        will return: 2
    
    """
    if '.' not in key:
        if key not in d:
            return None
        return d[key]
    base_key, sub_key = key.split('.', 1)
    if base_key not in d:
        return None
    sub_dict = d[base_key]
    if sub_dict is None:
        return None
    return get_nested_value(sub_dict, sub_key)

def get_row(line_contents, column_names):
    """Return a csv compatible row given column names and a dict."""
    row = []
    for column_name in column_names:
        line_value = get_nested_value(
                        line_contents,
                        column_name,
                        )
        # print (line_value)
        if isinstance(line_value, str):
            row.append(line_value)
        elif line_value is not None:
            row.append(line_value)
        else:
            row.append('')
    print(row)
    return row

if __name__ == '__main__':
    """Convert a yelp dataset file from json to csv."""

    parser = argparse.ArgumentParser(
            description='Convert Yelp Dataset Challenge data from JSON format to CSV.',
            )

    parser.add_argument(
            'json_file',
            type=str,
            help='The json file to convert.',
            )

    args = parser.parse_args()

    json_file = args.json_file
    csv_file = '{0}.csv'.format(json_file.split('.json')[0])

    column_names = get_superset_of_column_names_from_file(json_file)
    read_and_write_file(json_file, csv_file, column_names)

[meenurajapandian]

Thank you! Also, it worked for me only after I changed line 26 and line 17 to this: with open(json_file_path, encoding="utf-8") as fin:

[DimMani]

@mattdee @meenurajapandian After making the above changes I get this:

UnicodeEncodeError: 'charmap' codec can't encode character '\x9c' in position 112: character maps to

any thoughts on how to fix this?

[meenurajapandian]

@mattdee @meenurajapandian After making the above changes I get this:

UnicodeEncodeError: 'charmap' codec can't encode character '\x9c' in position 112: character maps to

any thoughts on how to fix this?

You need to include the encoding in every place that you have used the open() function. There are 3 places where they need to be included.

[CAVIND46016]

Totally agree with @meenurajapandian , in this case, encoding = 'latin1' worked fine for me.

[aftab740]

@meenurajapandian, i have python 3.6 and newbie to this language. Can you please help me how to set the json file path. I want to convert yelp data set. Please help with the full syntax.i will be very thankful to you. I need fully running code.

[CAVIND46016]

Slightly simpler version of json to csv conversion script can be found here: https://github.com/CAVIND46016/Yelp-Dataset-Analysis/blob/master/json_to_csv.py I have hard-coded the paths, so it should be simple to follow...

[meenurajapandian]

@meenurajapandian, i have python 3.6 and newbie to this language. Can you please help me how to set the json file path. I want to convert yelp data set. Please help with the full syntax.i will be very thankful to you. I need fully running code.

From the terminal, you can run the command $ python json_to_csv_converter.py yelp_academic_dataset.json

if the files are in the current directory or mention the path instead

$ python json_to_csv_converter.py path/yelp_academic_dataset.json

This is given in the documentation of the code.