为什么对象在列表中占据最后一个值？

Question

为什么对象在列表中占用最后一个值

ddd = [1,2]
master_list = []
for ridx in range(1):
    row_list = [] ; row_data = {} ; header_dic = {} ; 
    header_dic['background-color'] = 'green'
    row_list.append(header_dic)
    for metric_id in range(2):
        row_data['background-color'] = ddd[metric_id]
        row_list.append(row_data)
    master_list.append(row_list)

print(master_list)  

输出来了：

[[{'background-color': 'green'}, {'background-color': 2}, {'background-color': 2}]]

预期产量：

[[{'background-color': 'green'}, {'background-color': 1}, {'background-color': 2}]]

Answer 1

只需在内循环中移动row_data即可。

ddd = [1,2]
master_list = []
for ridx in range(1):
    row_list = [] ; header_dic = {} ; 
    header_dic['background-color'] = 'green'
    row_list.append(header_dic)

    for metric_id in range(2):
        row_data = {} 
        row_data['background-color'] = ddd[metric_id]
        row_list.append(row_data)
    master_list.append(row_list)

print(master_list)  

你会得到预期的输出：

[[{'background-color': 'green'}, {'background-color': 1}, {'background-color': 2}]]