这是使用纯Python的解决方案.

Here's a solution with plain python.

dlst = [{"id":1, "symbol":'A', "num":4}, {"id":2, "symbol":'A', "num":3},
    {"id":1, "symbol":'A', "num":5}, {"id":2, "symbol":'B', "num":1}]


# Create a dict where keys are tuples of (id,symbol), values are num

combined_d = {}

for d in dlst:
    id_sym = (d["id"], d["symbol"])
    if id_sym in combined_d:
        combined_d[id_sym] += d["num"]
    else:
        combined_d[id_sym] = d["num"]

# create a list of dictionaries from the tuple-keyed dict

result = []

for k, v in combined_d.items():
    d = {"id": k[0], "symbol": k[1], "num": v}
    result.append(d)

print(result)

它可以做您想要的，但是结果列表没有排序，因为它是根据字典构建的.

It does what you want, but the resulting list is not sorted, as it's built from a dictionary.