Pandas: Groupby to find first dates for each group
31. Grouping by Salesman ID to Find First Order Date
Write a Pandas program to split the following dataset using group by on 'salesman_id' and find the first order date for each group.
Test Data:
ord_no purch_amt ord_date customer_id salesman_id
0 70001 150.50 2012-10-05 3002 5002
1 70009 270.65 2012-09-10 3001 5003
2 70002 65.26 2012-10-05 3001 5001
3 70004 110.50 2012-08-17 3003 5003
4 70007 948.50 2012-09-10 3002 5002
5 70005 2400.60 2012-07-27 3002 5001
6 70008 5760.00 2012-09-10 3001 5001
7 70010 1983.43 2012-10-10 3004 5003
8 70003 2480.40 2012-10-10 3003 5003
9 70012 250.45 2012-06-27 3002 5002
10 70011 75.29 2012-08-17 3003 5003
11 70013 3045.60 2012-04-25 3001 5001
Sample Solution:
Python Code :
import pandas as pd
pd.set_option('display.max_rows', None)
#pd.set_option('display.max_columns', None)
df = pd.DataFrame({
'ord_no':[70001,70009,70002,70004,70007,70005,70008,70010,70003,70012,70011,70013],
'purch_amt':[150.5,270.65,65.26,110.5,948.5,2400.6,5760,1983.43,2480.4,250.45, 75.29,3045.6],
'ord_date': ['2012-10-05','2012-09-10','2012-10-05','2012-08-17','2012-09-10','2012-07-27','2012-09-10','2012-10-10','2012-10-10','2012-06-27','2012-08-17','2012-04-25'],
'customer_id':[3005,3001,3002,3009,3005,3007,3002,3004,3009,3008,3003,3002],
'salesman_id': [5002,5005,5001,5003,5002,5001,5001,5004,5003,5002,5004,5001]})
print("Original Orders DataFrame:")
print(df)
print("\nGroupby to find first order date for each group(salesman_id):")
result = df.groupby('salesman_id')['ord_date'].min()
print(result)
Sample Output:
Original Orders DataFrame:
ord_no purch_amt ord_date customer_id salesman_id
0 70001 150.50 2012-10-05 3005 5002
1 70009 270.65 2012-09-10 3001 5005
2 70002 65.26 2012-10-05 3002 5001
3 70004 110.50 2012-08-17 3009 5003
4 70007 948.50 2012-09-10 3005 5002
5 70005 2400.60 2012-07-27 3007 5001
6 70008 5760.00 2012-09-10 3002 5001
7 70010 1983.43 2012-10-10 3004 5004
8 70003 2480.40 2012-10-10 3009 5003
9 70012 250.45 2012-06-27 3008 5002
10 70011 75.29 2012-08-17 3003 5004
11 70013 3045.60 2012-04-25 3002 5001
Groupby to find first order date for each group(salesman_id):
salesman_id
5001 2012-04-25
5002 2012-06-27
5003 2012-08-17
5004 2012-08-17
5005 2012-09-10
Name: ord_date, dtype: object
For more Practice: Solve these Related Problems:
- Write a Pandas program to group the sales dataset by salesman_id and then extract the earliest order date for each group.
- Write a Pandas program to group by salesman_id and then use the min() function on the order date column to find the first order date.
- Write a Pandas program to split the dataframe by salesman_id and then apply a custom function to return the first order date per group.
- Write a Pandas program to group the dataset on salesman_id and then create a summary table showing the earliest order date for each salesman.
Go to:
Previous: Write a Pandas program to split the following dataset using group by on first column and aggregate over multiple lists on second column.
Next: Write a Pandas program to split a given dataset using group by on multiple columns and drop last n rows of from each group.
Python Code Editor:
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