Python - csv - Error: Sequence Expected

Question

I an attempting to use the python csv module to write a dictionary to a csv file.

My dictionary looks something like this:

{'PCIP': '192.168.1.4', 'DutIP': '192.168.1.6', 'timestamp': '20120410100340', 'start_time': '0.0', 
 'Transfer bytes': '59457090', 'Port': '5763', 'Lost Datagrams': '10575', 'Percent Lost Datagrams': 
 '20.727', 'PER': 20.727, 'Bandwidth bits': '51684334', 'Throughput': 51.684334, 'end_time': '9.2', 
 'Unknown': '41710', 'Jitter': '0.017', 'ID': '3', 'Total Datagrams': '51020'}

I get the error sequence expected when I attempt to write it.

Is there any way to do so?

def save_result_to_csv_file(self, file, data, header="", access_mode='ab'):
    """
    :param file: local file_name for csv-format logfile
    :type file: str
    :param data: a list or other datatype supported by csv.writerow() 
    :type data: list
    :param header: list containing row names
    :type header: list
    :param access_mode: 'a' append, 'w' write, 'ab' binary append, 'wb' binary write, 'r' read
    :type access_mode: str
    """
    #if file does not exist, start by writing the header row.

    log_file_obj = open(file, 'ab') 
    log_file_writer = csv.writer(log_file_obj)
    if not os.path.isfile(file):
        log_file_writer.writerow(header)
    log_file_writer.writerow(data)
    log_file_obj.flush()
    log_file_obj.close()

     # Labels (Compare to test_case_log_row definition, which matches row_labels)
    interval_data_labels = ["timestamp", "DutIP", "Port", "PCIP", "Unknown", "ID", "start_time", "end_time", "Transfer bytes", "Bandwidth bits"]
    summary_data_labels = interval_data_labels + ["Jitter", "Lost Datagrams", "Total Datagrams", "Percent Lost Datagrams"]
    timestamp_label = ["timestamp"]
    device_info_labels = [ "Device", "Device OS", "Device Bundle"]
    test_results_labels = ["Throughput (MBits/s)", "PER"]
    test_parameters_labels = ["pD.protocol", "pD.test_direction", "pD.execution_time", "pD.send_rate", "pD.packet_size", "pD.transfer_amount"]
    test_data_raw_labels = summary_data_labels
    row_labels = timestamp_label + device_info_labels + test_parameters_labels + test_results_labels + test_data_raw_labels

Answer 1

You could use the DictWriter object instead:

import csv

row = {'PCIP': '192.168.1.4', 'DutIP': '192.168.1.6', 'timestamp': '20120410100340', 'start_time': '0.0', 'Transfer bytes': '59457090', 'Port': '5763', 'Lost Datagrams': '10575', 'Percent Lost Datagrams': '20.727', 'PER': 20.727, 'Bandwidth bits': '51684334', 'Throughput': 51.684334, 'end_time': '9.2', 'Unknown': '41710', 'Jitter': '0.017', 'ID': '3', 'Total Datagrams': '51020'}

fp = open('/path/to/file', 'wb')
writer = csv.DictWriter(fp, fieldnames=row.keys())
writer.writerows([row])

Beware of the order of field names in row.keys().