python - 如何在熊猫中使用 groupby 选择某个值的频率？

Question

data.groupby('race/ethnicity')['lunch'].value_counts() 

在写这篇文章时，我得到以下输出：

race/ethnicity  lunch       
group A         standard         53
                free/reduced     36
group B         standard        121
                free/reduced     69
group C         standard        205
                free/reduced    114
group D         standard        167
                free/reduced     95
group E         standard         99
                free/reduced     41
Name: lunch, dtype: int64

如何仅获取每个组的“标准”条目的计数？

标签： pythonpandas