如何簡化 2 for 循環以獲得 dict object 值？

Question

有沒有辦法讓這兩個循環更簡單、更快、更干凈，比如List Comprehension,o(n)等。

def main:
  a={"res":
       [
        {"group":1,"ins":[{"name":"aa","id":123]},
        {"group":2,"ins":[{"name":"cc","id":456]}
     ]}
   result=[]
  for key in a["res"]:
     for i in key["ins"]
        result.append(i)
  return result

Answer 1

嘗試這個：

result = [i for key in a['res'] for i in key['ins']]

Answer 2

嘗試：

import numpy as np

# 3.21 µs ± 23.9 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)    
np.ravel([z["ins"] for z in a["res"]]).tolist()

輸出：

[{'name': 'aa', 'id': 123}, {'name': 'cc', 'id': 456}]

編輯：

您也可以嘗試更快的選擇：

# 372 ns ± 11.9 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
sum([z["ins"] for z in a["res"]],[])