如何在大熊猫的group_by中计算特定值？

Question

I have a dataframe and I use groupby to group it by Season. One of the columns of the original df is named Check and consists of True and False. My aim it to count the True values for each group and put it in the new dataframe.

import pandas as pd

df = ....
df['Check'] = df['Actual'] == df['Prediction']
grouped_per_year = df.groupby('Season')

df_2= pd.DataFrame()
df_2['Seasons'] = total_matches_per_year.keys()
df_2['Successes'] = ''
df_2['Total_Matches'] = list(grouped_per_year.size())
df_2['SR'] = df_2['Successes'] / df_2['Total_Matches']
df_2['Money_In'] = list(grouped_per_year['Money_In'].apply(sum))
df_2['Profit (%)'] = (df_profit['Money_In'] - df_profit['Total_Matches']) / df_profit['Total_Matches'] * 100.

I have tried:

successes_per_year = grouped_per_year['Pred_Check'].value_counts()

but I don't know how to get only the True count.

Answer 1

为了计算True ，您还可以使用sum （在执行数字运算时为True = 1和False = 0）：

grouped_per_year['Pred_Check'].sum()