使用 Python 从分类列中提取特定值

Question

Following is the sample table which consists of transaction data of bank customers. I need to create a separate column as annual salary of customer taking the data from txn_description column.

Customer_ID txn_description Amount Type
01           POS            345    Dr
02           SALARY         2000   Cr
03           INTER BANK     148    Dr
04           SALARY         1500   Cr
05           NEFT           289    Dr
06           SALARY         1800   Cr
01           NEFT           40     Dr
02           SALARY         2000   Cr
04           POS            69     Dr
04           SALARY         1500   Cr
06           SALARY         1800   Cr

Note: The transaction data is of three months. So the salary is credited to a particular customer's account thrice in this table for three months.

(Dr = Debit transaction and Cr = Credit transaction)

Answer 1

you could try this,

df= df[df["txn_description"]=="SALARY"]
df["Annual"] = df["Amount"]*12

O/P:

   Customer_ID txn_description  Amount  Annual
1            2          SALARY    2000   24000
3            4          SALARY    1500   18000
5            6          SALARY    1800   21600

Furthermore, If you want to apply it on original frame find this,

dic = df.set_index("Customer_ID")["Annual"].to_dict()

and apply it to actual dtaframe using df.map(dic)

Explanation:

1. First remove unwanted records, get only 'cr' or Salary records.
2. Now Dataframe has salary credited record of a month data of each customer. ie, customer id and amount is one to one map.
3. multiply amount with 12 to get annual value.
4. convert customer to annual value in dic and replace into actual frame.