# Source code for sections.section_01.csv_example

    """Example for writing datasets into CSV files.

    Demonstrates source datasets comprised of lists of dictionaries
    and lists of lists as separate functions. Example data is
    provided in line and will generate two identical CSVs as output.

    Example Usage:

        ``$ python csv_example.py``

    References:

        https://docs.python.org/3/library/csv.html
        https://docs.python.org/3/library/os.html

    """

    import csv

    """
    Copyright 2019 Chapin Bryce

    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation
    files (the "Software"), to deal in the Software without
    restriction, including without limitation the rights to use, copy,
    modify, merge, publish, distribute, sublicense, and/or sell copies
    of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
    """

    __author__ = 'Chapin Bryce'
    __date__ = 20190527
    __license__ = 'MIT Copyright 2019 Chapin Bryce'
    __desc__ = '''Sample script to write to CSV files.'''
    __docs__ = [
        'https://docs.python.org/3/library/csv.html',
        'https://docs.python.org/3/library/os.html'
    ]

    def write_csv_dicts(outfile, data, headers=None):
        """Writes a list of dictionaries to a CSV file.

        Arguments:
            outfile (str): Path to output file
            data (list): List of dictionaries to write to file
            headers (list): Header row to use. If empty, will use the
                first dictionary in the `data` list.
        """

        if not headers:
            # Use the first line of data
            headers = [str(x) for x in data[0].keys()]

        with open(outfile, 'w', newline="") as open_file:
            # Write only provided headers, ignore others
            csvfile = csv.DictWriter(open_file, headers,
                                     extrasaction='ignore')
            csvfile.writeheader()
            csvfile.writerows(data)

    def write_csv_lists(outfile, data, headers=None):
        """Writes a list of lists to a CSV file.

        Arguments:
            outfile (str): Path to output file
            data (list): List of lists to write to file
            headers (list): Header row to use. If empty, will use the
                first list in the `data` list.
        """

        with open(outfile, 'w', newline="") as open_file:
            # Write only provided headers, ignore others
            csvfile = csv.writer(open_file)
            for count, entry in enumerate(data):
                if count == 0:
                    # If headers are defined, write them, otherwise
                    # continue as they will be written anyways
                    if headers:
                        csvfile.writerow(headers)
                csvfile.writerow(entry)

    sample_dict_data = [
        {'id': '0', 'city': 'Boston', 'state': 'MA',
         'country': 'USA'},
        {'id': '1', 'city': 'New York', 'state': 'NY',
         'country': 'USA'},
        {'id': '2', 'city': 'Washington', 'state': 'DC',
         'country': 'USA'},
    ]

    write_csv_dicts('dict_test.csv', sample_dict_data)

    header_row = ['id', 'city', 'state', 'country']
    sample_list_data = [
        ['0', 'Boston', 'MA', 'USA'],
        ['1', 'New York', 'NY', 'USA'],
        ['2', 'Washington', 'DC', 'USA']
    ]

    write_csv_lists('list_test.csv', sample_list_data,
                    headers=header_row)