如何修复‘AttributeError: 'generator' object has no attribute 'nextRead'’错误？

错误原因 #

fastq.read(filename)返回的是生成器对象，这类对象没有nextRead()方法，这是触发AttributeError的直接原因。

修复代码 #

将原有的while循环替换为遍历生成器的for循环，这是Python处理生成器/迭代器的标准写法，更简洁且不易出错：

def stat(filename):
    reader = fastq.read(filename)
    total_count = 0
    q20_count = 0
    q30_count = 0
    # 直接遍历生成器获取每个read条目
    for read in reader:
        if not read:
            continue
        total_count += len(read[3])
        q20, q30 = qual_stat(read[3])
        q20_count += q20
        q30_count += q30

补充说明 #

如果一定要用手动迭代的方式（不推荐），需要用next()函数配合异常捕获（生成器耗尽时会抛出StopIteration）：

def stat(filename):
    reader = fastq.read(filename)
    total_count = 0
    q20_count = 0
    q30_count = 0
    while True:
        try:
            read = next(reader)
        except StopIteration:
            # 生成器遍历完毕，退出循环
            break
        total_count += len(read[3])
        q20, q30 = qual_stat(read[3])
        q20_count += q20
        q30_count += q30

你之前直接用next()出错，就是因为没处理生成器耗尽时的异常。

内容的提问来源于stack exchange，提问作者apcreyes