To Extract Substring from Column of DataFrame [closed]-CodePudding

Code Error

I am trying to extract 4 characters after First,second,third and so on occurance of '/' from Column of Dataframe

DataFrame

Can someone suggest possible code let me know what is error in my code

CodePudding user response：

Try with str.findall:

>>> df["NE Name"].str.findall(r"/([^/]{4})")
0                      [01HJ]
1    [01HL, 02HL, 03HL, 10HL]
2    [01HL, 02HL, 03HL, 10HL]
3    [01HL, 02HL, 03HL, 10HL]
4    [01HL, 02HL, 03HL, 10HL]
Name: NE Name, dtype: object

Input DataFrame:

>>> df
                                                     NE Name     Subrack ID  pattern
0   10100000/01HJ   0   01HJ
1   10100000/01HL&10100000/02HL&10100000/03HL&10100000/10HL               1     01HJ
2   10100000/01HL&10100000/02HL&10100000/03HL&10100000/10HL               0     01HJ
3   10100000/01HL&10100000/02HL&10100000/03HL&10100000/10HL               2     01HJ
4   10100000/01HL&10100000/02HL&10100000/03HL&10100000/10HL               3     01HJ

CodePudding user response：

Here is a basic approach without using regular expressions:

Use the str.split('/') method on the column to return a series of lists, each list containing the substrings in between the slashes.
apply a function to that series which returns the first four characters of each list element, except the first one. You can use the lambda keyword to concisely define such a function within the apply call.

import pandas as pd

df = pd.DataFrame({'col': ['101000000/01HJ', 
    '1010000/01HL&101/02HL&1010/03HL&04/10HL']})

df['col'].str.split('/').apply(lambda seq: [x[:4] for x in seq[1:]])

0                      [01HJ]
1    [01HL, 02HL, 03HL, 10HL]
Name: col, dtype: object