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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 pandas_df_to_biopython_seqrecord( df, id_col='uid', sequence_col='sequence', extra_data=None, alphabet=None, ):
 """Convert pandas dataframe to biopython seqrecord for easy writing. Parameters df : Dataframe Pandas dataframe to convert id_col : str column in dataframe to use as sequence label sequence_col str: column in dataframe to use as sequence data extra_data : list extra columns to use in sequence description line alphabet : biopython Alphabet object Returns ------- seq_records : List of biopython seqrecords. """

    seq_records = []

    for i, row in df.iterrows():
        # Tries getting sequence data. If a TypeError at the seqrecord
        # creation is thrown, it is assumed that this row does not contain
        # sequence data and therefore the row is ignored.
        try:
            # Get sequence
            seq = Seq(row[sequence_col], alphabet=alphabet)

            # Get id
            id = row[id_col]

            # Build a description
            description = ""
            if extra_data is not None:
                description = " ".join([row[key] for key in extra_data])

            # Build a record
            record = SeqRecord(
                seq=seq,
                id=id,
                description=description,
            )
            seq_records.append(record)
        except TypeError:
            pass

    return seq_records