我有一个基于不同气象站的多个变量(温度、压力等)的数据集,
stationID | Time | Temperature | Pressure |...
----------+------+-------------+----------+
123 | 1 | 30 | 1010.5 |
123 | 2 | 31 | 1009.0 |
202 | 1 | 24 | NaN |
202 | 2 | 24.3 | NaN |
202 | 3 | NaN | 1000.3 |
...
我想创建一个数据透视表来显示每个气象站的 NaN 和非 NaN 数量,这样:
stationID | nanStatus | Temperature | Pressure |...
----------+-----------+-------------+----------+
123 | NaN | 0 | 0 |
| nonNaN | 2 | 2 |
202 | NaN | 1 | 2 |
| nonNaN | 2 | 1 |
...
下面我展示了我到目前为止所做的工作,这些工作(以一种繁琐的方式)适用于温度。但是,如何才能使两个变量相同,如上所示?
import pandas as pd
import bumpy as np
df = pd.DataFrame({'stationID':[123,123,202,202,202], 'Time':[1,2,1,2,3],'Temperature':[30,31,24,24.3,np.nan],'Pressure':[1010.5,1009.0,np.nan,np.nan,1000.3]})
dfnull = df.isnull()
dfnull['stationID'] = df['stationID']
dfnull['tempValue'] = df['Temperature']
dfnull.pivot_table(values=["tempValue"], index=["stationID","Temperature"], aggfunc=len,fill_value=0)
输出是:
----------------------------------
tempValue
stationID | Temperature
123 | False 2
202 | False 2
| True 1
最佳答案
更新:感谢 @root :
In [16]: df.groupby('stationID')[['Temperature','Pressure']].agg([nans, notnans]).astype(int).stack(level=1)
Out[16]:
Temperature Pressure
stationID
123 nans 0 0
notnans 2 2
202 nans 1 2
notnans 2 1
原答案:
In [12]: %paste
def nans(s):
return s.isnull().sum()
def notnans(s):
return s.notnull().sum()
## -- End pasted text --
In [37]: df.groupby('stationID')[['Temperature','Pressure']].agg([nans, notnans]).astype(np.int8)
Out[37]:
Temperature Pressure
nans notnans nans notnans
stationID
123 0 2 0 2
202 1 2 2 1
关于Python pandas - 构建多元数据透视表以显示 NaN 和非 NaN 的计数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38595578/