how to subtract two values in my dataframe-CodePudding

I get this csv from my program and i want to get the "thickness"/difference of each of my Depth values. So for example 3998 - 4002 = -4 is there a way to use this csv or is it useless because i couldn't find anything that would solve my problem.

df = pd.read_csv ('/PermeabilityData.csv',sep=";") 
display(df)

a = df['Depth [ft]'].loc[data.index[0]]
    Depth [ft]  Permeability [mD]
0   3998-4002   180
1   4002-4004   150
2   4004-4006   200
3   4006-4008   140
4   4008-4010   160

CodePudding user response：

A possible solution:

df['Depth [ft]'].map(eval)

Output:

0   -4
1   -2
2   -2
3   -2
4   -2
Name: Depth [ft], dtype: int64

CodePudding user response：

This could also be done:

pd.eval(df.iloc[:,0])

[-4, -2, -2, -2, -2]

CodePudding user response：

In lieu of using the eval, here is one way to do it

df['Depth[ft]'].str.split('-',expand=True).astype(int).apply(lambda x: x[0]-x[1], axis=1)

0   -4
1   -2
2   -2
3   -2
4   -2
dtype: int32