比较两个列表项，其中列表包含字典项

Question

我有两个列表：

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

我想这两个列表，如果value1匹配，那么它将返回列表b的所有键之间的比较。我想这样的结果：

c= ['x','z'] 

Answer 1

我读这是：“在名单b返回从字典d所有键k的列表，使得k在d值相同的值从列表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

在一些字典中一些关键的您可以实现这样的事情：

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) 

输出：

['x', 'z'] 

---

即相当于：

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)