如下面的例子：
我想将这样包含bytes的行中的packet替换成bytes.

    **rx_bytes2_blob = BlobField('rx proto2 packets' , item_type = int)**--->rx_bytes2_blob = BlobField('rx proto2 *bytes*' , item_type = int)

我查了下网上有:g/bytes/s/packets/bytes/g;但是这样做不符合我的习惯，我一般是从xx行到yy行进行替换。
试了下，xx,yy/bytes/s/packets/bytes/g;大概是将其中所有的packets都转成bytes了。

    rx_proto2_blob = BlobField('rx proto2, bytes is the 2nd, ...', item_type = int)
    rx_packets2_blob = BlobField('rx proto2 packets' , item_type = int)
    rx_bytes2_blob = BlobField('rx proto2 packets' , item_type = int)

    rx_proto3_blob = BlobField('rx proto3, bytes is the 3rd, ...', item_type = int)
    rx_packets3_blob = BlobField('rx proto3 packets' , item_type = int)
    rx_bytes3_blob = BlobField('rx proto3 packets' , item_type = int)

    rx_proto4_blob = BlobField('rx proto4, bytes is the largest, ...', item_type = int)
    rx_packets4_blob = BlobField('rx proto4 packets' , item_type = int)
    rx_bytes4_blob = BlobField('rx proto4 packets' , item_type = int)

    rx_proto5_blob = BlobField('rx proto5, bytes is the largest, ...', item_type = int)
    rx_packets5_blob = BlobField('rx proto5 packets' , item_type = int)
    rx_bytes5_blob = BlobField('rx proto5 packets' , item_type = int)

    rx_proto6_blob = BlobField('rx proto6, bytes is the largest, ...', item_type = int)
    rx_packets6_blob = BlobField('rx proto6 packets' , item_type = int)
    rx_bytes6_blob = BlobField('rx proto6 packets' , item_type = int)