python-如何检查文件对象是否为随机访问

我有一个接受任意文件句柄的函数,或者加载所有数据,或者如果对象支持随机访问,则允许延迟加载数据.

class DataLoader:
    def __init__(self, file):
        self.file = file
        self.headers = {}
    def load_data(self):
        # header is a hashable (e.g. namedtuple with name, size, offset)
        header = self.load_next_header()
        if self.file.random_access:
            # Return and load the data only as necessary if you can
            self.headers[header.name] = (header, None)
            self.file.seek(header.size + self.file.tell())
        else:
            # Load the data up front if you can't
            self.headers[header.name] = (header, self.file.read(header.size))

如何检查文件对象是否支持随机访问？

解决方法:

您可以使用seekable方法来检查文件是否支持随机访问.

seekable()

Return True if the stream supports random access. If False, seek(), tell() and truncate() will raise OSError.

标签：random-access,python-3-x,python
来源： https://codeday.me/bug/20191025/1927486.html