Python - 通过复制创建新的 DF 列 - 现有列值的部分字符串匹配

Question

I have a dataframe with 50k records with one of the column value like below.

DF\n

Index.       COLUMN\n

0.       ABC-1M-Deliveryorder
1.       KGF-ORDERDelivery-2Y
2.       DEFGHIABC1M-OPEN
3.       KGFABC
4.       ABC-3Y-ORDER

I am looking for key words - 3Y , 3M , 2Y and 1Y from COLUMN and if found the values need to be copied to a new DF column name TENOR with 3Y , 3M , 1M etc. In case not found it can show FALSE or NAN

I tried with below code

df['Tenor'] = ""\n

df['Tenor'] = df.column.apply(lambda x: x in ['3Y','3M,'1Y','1M']

This returns as FALSE in all rows for the new column. Can you please advise what is best way to meet my requirement?

Answer 1

You can use pandas.Series.str.contains with a regex:

import pandas as pd

df = pd.DataFrame(dict(
    COLUMN = [
        'ABC-1M-Deliveryorder','KGF-ORDERDelivery-2Y',
        'DEFGHIABC1M-OPEN', 'KGFABC', 'ABC-3Y-ORDER'
    ]
))

df['Tenor'] = df['COLUMN'].str.contains('3Y|3M|2Y|1Y|1M', regex=True)

Edit: OP asked the follow up question:

The above code snippet is returning TRUE wherever the column finds the string 2Y, 3Y etc.. But i need the output as below Index Column NEW 0 ABC-1M-Deliveryorder 1M 1 KGF-ORDERDelivery-2Y 2Y 2 DEFGHIABC1M-OPEN 1M 3 KGFABC Nan 4 ABC-3Y-ORDER 3Y

If that is the case then you may want to use a custom function and pandas.Series.apply like so:

import pandas as pd

df = pd.DataFrame(dict(
    COLUMN = [
        'ABC-1M-Deliveryorder','KGF-ORDERDelivery-2Y',
        'DEFGHIABC1M-OPEN', 'KGFABC', 'ABC-3Y-ORDER'
    ]
))

def find_substring(x):
    for y in ('3Y','3M','2Y','1Y','1M'):
        if y in x:
            return y

df['Tenor'] = df['COLUMN'].apply(find_substring)

print(df)

output:

                 COLUMN Tenor
0  ABC-1M-Deliveryorder    1M
1  KGF-ORDERDelivery-2Y    2Y
2      DEFGHIABC1M-OPEN    1M
3                KGFABC  None
4          ABC-3Y-ORDER    3Y

python tutor link to example

Answer 2

The above code snippet is returning TRUE wherever the column finds the string 2Y, 3Y etc..

But i need the output as below code output

''''

Index Column NEW 0 ABC-1M-Deliveryorder 1M 1 KGF-ORDERDelivery-2Y 2Y 2 DEFGHIABC1M-OPEN 1M 3 KGFABC Nan 4 ABC-3Y-ORDER 3Y

''''