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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 trim_seqs(input_seqs, trim_len, left_trim_len):
 """Trim FASTA sequences to specified length. Parameters input_seqs : iterable of (str, str) The list of input sequences in (label, sequence) format trim_len : int Sequence trimming length. Specify a value of -1 to disable trimming. left_trim_len : int Sequence trimming from the 5' end. A value of 0 will disable this trim. Returns ------- Generator of (str, str) The trimmed sequences in (label, sequence) format """

    # counters for the number of trimmed and total sequences
    logger = logging.getLogger(__name__)

    okseqs = 0
    totseqs = 0

    if trim_len < -1:
        raise ValueError("Invalid trim_len: %d" % trim_len)

    for label, seq in input_seqs:
        totseqs += 1

        if trim_len == -1:
            okseqs += 1
            yield label, seq
        elif len(seq) >= trim_len:
            okseqs += 1
            yield label, seq[left_trim_len:trim_len]

    if okseqs < 0.01*totseqs:
        logger = logging.getLogger(__name__)
        errmsg = 'Vast majority of sequences (%d / %d) are shorter ' \
                 'than the trim length (%d). ' \
                 'Are you using the correct -t trim length?' \
                 % (totseqs-okseqs, totseqs, trim_len)
        logger.warn(errmsg)
        warnings.warn(errmsg, UserWarning)
    else:
        logger.debug('trimmed to length %d (%d / %d remaining)'
                     % (trim_len, okseqs, totseqs))