How can I slice column values based on first & last character location indicators from two other columns?
Here is the code for a sample df:
import pandas as pd
d = {'W': ['abcde','abcde','abcde','abcde']}
df = pd.DataFrame(data=d)
df['First']=[0,0,0,0]
df['Last']=[1,2,3,5]
df['Slice']=['a','ab','abc','abcde']
print(df.head())
Code output:
Desired Output:
I am not sure if this will be faster, but a similar approach would be:
df['Slice'] = df.apply(lambda x: x[0][x[1]:x[2]],axis=1)
Briefly, you go through each row (axis=1) and apply a custom function. The function takes the row (stored as x), and slices the first element using the second and third elements as indices for the slicing (that's the lambda part). I will be happy to elaborate more if this isn't clear.
Just do it with for loop , you may worry about the speed , please check For loops with pandas - When should I care?
df['Slice']=[x[y:z]for x,y,z in zip(df.W,df.First,df.Last)]
df
Out[918]:
W First Last Slice
0 abcde 0 1 a
1 abcde 0 2 ab
2 abcde 0 3 abc
3 abcde 0 5 abcde
