如何在不使用biopython的情况下编写脚本来总结多fasta文件中的信息？

import os

def parse_fasta(file_path):
    sequences = {}
    current_seq = None

    with open(file_path, 'r') as f:
        for line in f:
            line = line.strip()
            if line.startswith('>'):
                current_seq = line[1:]
                sequences[current_seq] = ''
            else:
                sequences[current_seq] += line

    return sequences

def summarize_fasta_files(directory):
    summary = {}

    for filename in os.listdir(directory):
        if filename.endswith('.fasta'):
            file_path = os.path.join(directory, filename)
            sequences = parse_fasta(file_path)
            
            for seq_name, seq_data in sequences.items():
                if seq_name not in summary:
                    summary[seq_name] = {'count': 0, 'total_length': 0}
                summary[seq_name]['count'] += 1
                summary[seq_name]['total_length'] += len(seq_data)

    return summary

fasta_directory = '/path/to/fasta/files'
summary = summarize_fasta_files(fasta_directory)

for seq_name, seq_summary in summary.items():
    print(f"Sequence {seq_name} appears in {seq_summary['count']} files with a total length of {seq_summary['total_length']}.")