数据框遍历python

Question

Data for bank account

accntid    transcode    transamt balance
1            Credit        20      4000
1            Debit         50
1            Credit        80
2            Debit         60      5000
2            Credit        40
2            Debit         120
2            Credit        130

嗨，大家好。我有一个包含上述数据的数据框，我想根据下一行的交易代码和交易金额来更新余额。知道如何在Dataframe上来回遍历

Answer 1

IIUC：

df1 = df.assign(transamt = np.where(df['transcode'] == 'Debit',-1,1) * df['transamt'])

df1['balance1'] = (df1.balance
                    .fillna(df1.groupby('accntid', group_keys=False)
                               .apply(lambda x: x.balance.fillna(df1.transamt).cumsum())))

print(df1)

输出：

   accntid transcode  transamt  balance  balance1
0        1    Credit        20   4000.0    4000.0
1        1     Debit       -50      NaN    3950.0
2        1    Credit        80      NaN    4030.0
3        2     Debit       -60   5000.0    5000.0
4        2    Credit        40      NaN    5040.0
5        2     Debit      -120      NaN    4920.0
6        2    Credit       130      NaN    5050.0