问题描述
我只是想获取给定列中某个值的行数,例如:
CSV 数据:
'Occupation','data'
'Carpenter','data1'
'Carpenter','data2'
'Carpenter','data3'
'Painter','data1'
'Painter','data2'
'Programmer','data1'
'Programmer','data3'
'Programmer','data4'
计划:
filename = "./data/TestGroup.csv"
df = pd.read_csv(filename)
print(df.head())
print("Computing stats by HandRank... ")
df_stats = df[['data']].groupby(['Occupation']).agg(['count'])
# also tried: df_stats = df[['Occupation']].groupby(['Occupation']).agg(['count'])
print(df_stats.head())
如何获取变量中的计数? .groupby 和 .agg 是否返回另一个数据帧?
'Occupation' 'data'
0 'Carpenter' 'data1'
1 'Carpenter' 'data2'
2 'Carpenter' 'data3'
3 'Painter' 'data1'
4 'Painter' 'data2'
Computing stats by HandRank...
Traceback (most recent call last):
File "C:\Apps\PokerHandGenerator_copy_not_Source\Server\TestPandasGroupBy.py",line 17,in <module>
df_stats = df.groupby(['Occupation']).agg(['count'])
File "C:\Apps\ProcessData\venv\lib\site-packages\pandas\core\frame.py",line 6714,in groupby
return DataFrameGroupBy(
File "C:\Apps\ProcessData\venv\lib\site-packages\pandas\core\groupby\groupby.py",line 560,in __init__
grouper,exclusions,obj = get_grouper(
File "C:\Apps\ProcessData\venv\lib\site-packages\pandas\core\groupby\grouper.py",line 811,in get_grouper
raise KeyError(gpr)
KeyError: 'Occupation'
df.head() 显示它使用“职业”作为我的列名。
解决方法
Pandas 将第一列视为“职业”而不是职业。
使用这个:-
df_stats = df.groupby("'Occupation'").agg(['count'])
而不是使用这个:-
df_stats = df[['data']].groupby(['Occupation']).agg(['count'])