比較兩個列表項，其中列表包含字典項

Question

我有兩個列表：

a = [{'1':'value1'},{'2':'value2'}] 
b = [{'x':'value1'},{'y':'hello'},{'z':'value1'}] 

我想這兩個列表，如果value1匹配，那麼它將返回列表b的所有鍵之間的比較。我想這樣的結果：

c= ['x','z'] 

Answer 1

我讀這是：「在名單b返回從字典d所有鍵k的列表，使得k在d值相同的值從列表a「

val_set = {v for d in a for v in d.values()} 
output = [k for d in b for k, v in d.items() if v in val_set] 
print(output) 
#['x', 'z'] 

Answer 2

在一些字典中一些關鍵的您可以實現這樣的事情：

a = [{'1':'value1'},{'2':'value2'}] 
b = [{'x':'value1'},{'y':'hello'},{'z':'value1'}] 
c = [w.keys()[0] for q in a for w in b if q.values()[0] == w.values()[0]] 
print(c) 

輸出：

['x', 'z'] 

---

即相當於：

a = [{'1':'value1'},{'2':'value2'}] 
b = [{'x':'value1'},{'y':'hello'},{'z':'value1'}] 
c = [] 
for q in a: 
    for w in b: 
     if q.values()[0] == w.values()[0]: 
      c.append(w.keys()[0]) 
print(c)