类型错误：列表索引必须是整数或切片，而不是 str

Question

#read from csv top and bottom
def get_interval(row):

   return df[(df['DEPTH']>=row['top']) & (df['DEPTH']<=row['bottom'])]

#Combine all intervals 
intervals = list(perf.apply(get_interval, axis=1))
 
pd.concat(intervals)

#summ al values in kh column in my data frame 
x =  intervals['kh'].sum()

I got:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-22-d3a755411e27> in <module>
      1 #Displaying and Summ the kh over the selected interval
      2 
----> 3 x =  intervals['kh'].sum()
      4 
      5 #print('\033[93m' + '\033[4m'+ '\033[1m' + 'Total kh =' + '\033[0m', GHZL_13 )

TypeError: list indices must be integers or slices, not str

I was expecting a sum from one column (kh) in my data frame

Answer 1

I think you are just trying to get the sum of the kh column for the rows that satisfy:

top <= DEPTH <= bottom (maybe you've got these the wrong way round? but I will use this).

You can do this in one line using .loc[] to filter the dataframe on those rows, and the kh column, then use .sum() to get the sum like this:

df.loc[(df['DEPTH']>=df['top']) & (df['DEPTH']<=df['bottom']), 'kh'].sum()

for example, if df is:

df = pd.DataFrame({'DEPTH':[10, 15, 13],
                   'top':[5, 7, 10],
                   'bottom':[20, 7, 15],
                   'kh' : [10, 23, 17]})

   DEPTH  top  bottom  kh
0     10    5      20  10
1     15    7       7  23
2     13   10      15  17

then the.loc[] filtering of the rows ( df.loc[(df['DEPTH']>=df['top']) & (df['DEPTH']<=df['bottom'])] ) gives:

   DEPTH  top  bottom  kh
0     10    5      20  10
2     13   10      15  17

You can then specify the kh column, and use.sum() (as described above) to get the sum of the kh column in the filtered df, which is 27 in this case.