FASTQ质控代码示例：Python实现

{"title":"FASTQ质控代码示例：Python实现","description":"本示例使用Python代码对FASTQ文件进行质量控制，通过计算序列平均质量分数，判断是否低于设定阈值，并输出低质量序列信息。","keywords":"FASTQ质控, FASTQ质量控制, Python代码, 序列质量, 平均质量分数, 阈值","content":"以下是一个简单的Python代码示例，用于对FASTQ文件进行质量控制。\n\npython\ndef quality_control(fastq_file, threshold):\n with open(fastq_file, 'r') as f:\n line_num = 0\n while True:\n line_num += 1\n line1 = f.readline().strip()\n line2 = f.readline().strip()\n line3 = f.readline().strip()\n line4 = f.readline().strip()\n \n if not line4:\n break\n \n quality_scores = [ord(char) - 33 for char in line4]\n average_quality = sum(quality_scores) / len(quality_scores)\n \n if average_quality < threshold:\n print(f"Low quality sequence found at line {line_num}")\n print(f"Average quality: {average_quality}")\n print("Sequence:")\n print(line2)\n print("Quality:")\n print(line4)\n print()\n\n\n使用示例：\n\npython\nfastq_file = "sample.fastq"\nthreshold = 30\nquality_control(fastq_file, threshold)\n\n\n上述代码将打开指定的FASTQ文件，并逐行读取文件内容。然后，它将解析每个序列的质量行，并计算平均质量。如果平均质量低于设定的阈值，则将打印出相应的序列及其质量信息。"}