根据字符在数据框中创建新记录

Question

我在pandas数据框中有字段，如下面的示例数据。其中一个字段中的值是具有/ count（某物）形式的分数。我想分割下面的示例输出值，并创建新记录。基本上是分子和分母。有些值甚至有多个/，比如count（something）/ count（thing）/ count（dog）。所以我想把这个值分成3条记录。任何有关如何做到这一点的提示将不胜感激。

Sample Data:

SampleDf=pd.DataFrame([['tom','sum(stuff)/count(things)'],['bob','count(things)/count(stuff)']],columns=['ReportField','OtherField'])


Example Output:

OutputDf=pd.DataFrame([['tom1','sum(stuff)'],['tom2','count(things)'],['bob1','count(things)'],['bob2','count(stuff)']],columns=['ReportField','OtherField'])

Answer 1

可能有更好的方法，但试试这个，

df = df.set_index('ReportField')
df = pd.DataFrame(df.OtherField.str.split('/', expand = True).stack().reset_index(-1, drop = True)).reset_index()

你得到了

    ReportField 0
0   tom         sum(stuff)
1   tom         count(things)
2   bob         count(things)
3   bob         count(stuff)

Answer 2

一种可能的方式如下：

# split and stack 
new_df = pd.DataFrame(SampleDf.OtherField.str.split('/').tolist(), index=SampleDf.ReportField).stack().reset_index()
print(new_df)

输出：

    ReportField  level_1          0
0         tom        0     sum(stuff)
1         tom        1  count(things)
2         bob        0  count(things)
3         bob        1   count(stuff)

现在，将ReportField与level_1合并：

# combine strings for tom1, tom2 ,.....
new_df['ReportField'] = new_df.ReportField.str.cat((new_df.level_1+1).astype(str))

# remove level column
del new_df['level_1']
# rename columns
new_df.columns = ['ReportField', 'OtherField']
print (new_df)

输出：

    ReportField     OtherField
0        tom1       sum(stuff)
1        tom2    count(things)
2        bob1    count(things)
3        bob2     count(stuff)

Answer 3

您可以使用：

• split与expand=True新DataFrame
• 按stack和reset_index
重新塑造
• 将计数器添加到ReportField列，并astype
转换为str
• 按drop
删除辅助列level_1

OutputDf = SampleDf.set_index('ReportField')['OtherField'].str.split('/',expand=True)
                   .stack().reset_index(name='OtherField')
OutputDf['ReportField'] = OutputDf['ReportField'] + OutputDf['level_1'].add(1).astype(str)
OutputDf = OutputDf.drop('level_1', axis=1)
print (OutputDf)
  ReportField     OtherField
0        tom1     sum(stuff)
1        tom2  count(things)
2        bob1  count(things)
3        bob2   count(stuff)