csv.join_file_xam

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Example Joining Two CSV Tables

Example Source Code

#
# import at_cascade with a preference current directory version
current_directory = os.getcwd()
if os.path.isfile( current_directory + '/at_cascade/__init__.py' ) :
    sys.path.insert(0, current_directory)
import at_cascade
#
def main() :
    #
    # result_dir
    result_dir = 'build/example/csv'
    at_cascade.empty_directory(result_dir)
    #
    # left_file
    left_file = 'build/example/csv/left_file.csv'
    left_table = [
        { 'age' : '40',  'time' : '2000', 'sex' : 'female' },
        { 'age' : '50',  'time' : '2000', 'sex' : 'female' },
        { 'age' : '60',  'time' : '2000', 'sex' : 'female' },
    ]
    at_cascade.csv.write_table(left_file, left_table)
    #
    # right_file
    right_file = 'build/example/csv/right_file.csv'
    right_table = [
        { 'meas_value' : '1.0', 'sex' : 'female' },
        { 'meas_value' : '2.0', 'sex' : 'both' },
        { 'meas_value' : '2.0', 'sex' : 'male' },
    ]
    at_cascade.csv.write_table(right_file, right_table)
    #
    # result_file
    result_file = 'build/example/csv/result_file.csv'
    at_cascade.csv.join_file(left_file, right_file, result_file)
    #
    # result_table
    result_table = at_cascade.csv.read_table(result_file)
    #
    # check
    assert len(result_table) == len(left_table)
    assert list( result_table[0].keys() ) == \
        [ 'age', 'time', 'sex', 'meas_value' ]
    for index in range( len(left_table) ) :
        left_row   = left_table[index]
        right_row  = right_table[index]
        result_row = result_table[index]
        for key in result_row :
            if key in right_row :
                assert result_row[key] == right_row[key]
            else :
                assert result_row[key] == left_row[key]
    #
#
# Without this, the mac will try to execute main on each processor.
if __name__ == '__main__' :
    main()
    print('csv_join_file_xam: OK')