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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def read_all(pattern='data/lightbulb-*.csv'):
 """Read all of the CSVs in a directory matching the filename pattern as TimeSeries. """

    result = []
    for filename in glob.iglob(pattern):
        print('reading', filename, file=sys.stderr)
        ts = traces.TimeSeries.from_csv(
            filename,
            time_column=0,
            time_transform=parse_iso_datetime,
            value_column=1,
            value_transform=int,
            default=0,
        )
        ts.compact()
        result.append(ts)
    return result