python – 使用pandas groupby功能查找可盈利投资的百分比

我有像这样的pandas DataFrame;它显示了股票投资的历史.在Profit列中,1表示有利可图,0表示亏损.

Stock  Year   Profit  Count
 AAPL  2012    0       23
 AAPL  2012    1       19
 AAPL  2013    0       20
 AAPL  2013    1       10
GOOG   2012    0       26
GOOG   2012    1       20
GOOG   2013    0       23
GOOG   2013    1       11

我必须找出有利可图的投资百分比：

Stock  Year   Profit  CountPercent
 AAPL  2012    1       38.77
 AAPL  2013    1       33.33
GOOG   2012    1       43.47
GOOG   2013    1       32.35

我尝试在this post中使用该方法
 但它显示’TypeError：两个MultiIndex对象之间的连接是不明确的’.

解决方法:

我已将您的数据加载到名为“stocks”的数据框中.

# Get the count of profitable Trades, indexed by stock+year:
count_profitable = stocks[ stocks['Profit']==1 ].set_index(['Stock','Year']).Count
# Get the count of all Trades, indexed by stock + year:
count_all        = stocks.groupby(['Stock','Year']).Count.sum()
# Render nice percentages
pandas.options.display.float_format = '{:.2f}%'.format 
(count_profitable/count_all) * 100

这将产生：

Stock  Year
AAPL   2012   45.24%
       2013   33.33%
GOOG   2012   43.48%
       2013   32.35%
Name: Count, dtype: float64