Question

我有一个dicts列表（列表中每个条目都是dict）。每个dict都有一组不同的键，因此一个dict可能有一个与列表中其他dicts不同的键。我试图在此列表中找到特定的dicts顺序。基本上，该列表来自wireshark捕获，我想查找某些数据包。列表中间有一个特定的数据包序列。此外，在此序列中，有一些我希望忽略/过滤的数据包。实现这一目标的最佳方法是什么？我有一些伪代码写在下面：

for i in range(len(packets)):
    p = packets[i].fields # This method turns the packet object into a dict
    try:
        if p['some_field'] == A_CONSTANT_I_HAVE_DEFINED:
            # Mark this packet as part of the sequence
            # Save as part of sequence
            first_packet = p
            # Do not check for this condition again! I want to go to the next
            # iteration once I come across a packet with similar property
            # (the equality satisfied)
        if p['some_field'] == ANOTHER_CONSTANT:
            # Same as above
            second_packet = p
        if p['some_other_field'] == SOME_OTHER_CONSTANT:
            # Same as above
            third_packet = p
     except KeyError as err:
         pass

# Now I should have first_packet, second_packet and third_packet
# The list packets will always have the sequence of packets I am looking for

请注意我的字段some_field和some_other_field是如何不同的，以及不同的常量：A_CONSTANT_I_HAVE_DEFINED, ANOTHER_CONSTANT, SOME_OTHER_CONSTANT。请注意，some_field可能不在列表中的每个项目中，some_other_field

也相同

Answer 1

first_packet = None
second_packet = None
third_packet = None
packets_found =  0

for packet in packets:
    val = packet.get('some_field', None)
    if (val == A_CONSTANT_I_HAVE_DEFINED) and (first_packet is not None):
        first_packet = packet
        packets_found += 1
    elif (val == ANOTHER_CONSTANT) and (second_packet is not None):
        second_packet = packet
        packets_found += 1
    elif (packet.get('some_other_field', None) == SOME_OTHER_CONSTANT) and (third_packet is not None):
        third_packet = packet
        packets_found += 1

    if packets_found == 3:
        break

Answer 2

我不清楚，这可能会有所帮助：

a = [{'a': 1}, {'a':1, 'b':1}, {'c':1}]
filtered_list = filter(lambda x: x.get('a') or x.get('b'), a)
# OP [{'a': 1}, {'a': 1, 'b': 1}]

希望这有帮助。

每个具有不同键的dicts列表，是查找序列序列的最佳方式

2 个答案: