python - 使用列表索引多索引数据帧

Question

我创建了一个多索引的 pandas 数据框，如下所示:

m_index = ['time_remaining', 'inventory']
for i in indicators:
    m_index.append(i.name)
cols = []
for col in m_index:
    cols.append(col)
cols.append('action')
cols.append('cost')

optimal_actions = pd.DataFrame(columns=cols)
optimal_actions.set_index(m_index, inplace=True)

然后我有一个索引值列表:

state_variables = [indicator.value for indicator in indicators]
state = [time_remaining, i*trade_size]      
state.extend(state_variables)

我正在尝试将值列表索引的行设置为一个值:

state = [300, 1, 1.0]
optimal_actions.loc[state] = [-1, -0.2]

这给了我一个严重的错误:

ValueError: zero-size array to reduction operation maximum which has no identity

任何帮助将不胜感激!

Answer 1

如果有人需要这个，我最终通过用元组而不是列表对多索引进行索引来解决它。所以上面的代码修改为:

state = [300, 1, 1.0]
optimal_actions.loc[tuple(state)] = [-1, -0.2]