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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 pgimport( filename, database_uri, table_name, encoding="utf-8", dialect=None, create_table=True, schema=None, callback=None, timeout=0.1, chunk_size=8388608, max_samples=10000, ):
 """Import data from CSV into PostgreSQL using the fastest method Required: psql command """


    fobj = open_compressed(filename, mode="r", encoding=encoding)
    sample = fobj.read(chunk_size)

    if dialect is None:  # Detect dialect
        dialect = rows.plugins.csv.discover_dialect(
            sample.encode(encoding), encoding=encoding
        )
    elif isinstance(dialect, six.text_type):
        dialect = csv.get_dialect(dialect)

    if schema is None:
        # Detect field names
        reader = csv.reader(io.StringIO(sample), dialect=dialect)
        field_names = [slug(field_name) for field_name in next(reader)]

    else:
        field_names = list(schema.keys())

    if create_table:
        if schema is None:
            data = [
                dict(zip(field_names, row))
                for row in itertools.islice(reader, max_samples)
            ]
            table = rows.import_from_dicts(data)
            field_types = [table.fields[field_name] for field_name in field_names]
        else:
            field_types = list(schema.values())

        columns = [
            "{} {}".format(name, POSTGRESQL_TYPES.get(type_, DEFAULT_POSTGRESQL_TYPE))
            for name, type_ in zip(field_names, field_types)
        ]
        create_table = SQL_CREATE_TABLE.format(
            table_name=table_name, field_types=", ".join(columns)
        )
        execute_command(get_psql_command(create_table, database_uri=database_uri))

    # Prepare the `psql` command to be executed based on collected metadata
    command = get_psql_copy_command(
        database_uri=database_uri,
        dialect=dialect,
        direction="FROM",
        encoding=encoding,
        header=field_names,
        table_name=table_name,
    )
    rows_imported, error = 0, None
    fobj = open_compressed(filename, mode="rb")
    try:
        process = subprocess.Popen(
            shlex.split(command),
            stdin=subprocess.PIPE,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
        )
        data = fobj.read(chunk_size)
        total_written = 0
        while data != b"":
            written = process.stdin.write(data)
            total_written += written
            if callback:
                callback(written, total_written)
            data = fobj.read(chunk_size)
        stdout, stderr = process.communicate()
        if stderr != b"":
            raise RuntimeError(stderr.decode("utf-8"))
        rows_imported = int(stdout.replace(b"COPY ", b"").strip())

    except FileNotFoundError:
        raise RuntimeError("Command `psql` not found")

    except BrokenPipeError:
        raise RuntimeError(process.stderr.read().decode("utf-8"))

    return {"bytes_written": total_written, "rows_imported": rows_imported}