__init__.py 文件源码

def read_random_line(f):
    import os

    chunk_size = 16
    with open(f, 'rb') as f_handle:
        f_handle.seek(0, os.SEEK_END)
        size = f_handle.tell()
        # i = random.randint(0, size)
        i = u_randint(0, size)
        while True:
            i -= chunk_size
            if i < 0:
                chunk_size += i
                i = 0
            f_handle.seek(i, os.SEEK_SET)
            d = f_handle.read(chunk_size)
            i_newline = d.rfind(b'\n')
            if i_newline != -1:
                i += i_newline + 1
                break
            if i == 0:
                break
        f_handle.seek(i, os.SEEK_SET)
        return f_handle.readline()