如何在多变量表格中合并重复项并求和

I've got you covered! Here are three straightforward methods to achieve your desired result, depending on the tool you're using:

1. Excel/Google Sheets (Pivot Table Method) #

This is the easiest built-in way for spreadsheet users:

• Step 1: Select your entire dataset (including headers: Item, Class, A, B, C).
• Step 2: In Excel, go to Insert > PivotTable; in Google Sheets, go to Data > Pivot table.
• Step 3: In the PivotTable editor:
  • Drag the Class field to the Rows section.
  • Drag A, B, and C each to the Values section. By default, they might show as "Count"—click the dropdown for each value field and select Sum instead.
• Result: You’ll get a clean table with merged Class names and summed values for A, B, C exactly as you wanted.

2. Python (Pandas Library) #

If you prefer code-based data manipulation, pandas makes this a breeze:

import pandas as pd

# Load your data (replace this with reading from a file if needed)
data = {
    'Item': ['AA', 'BB', 'CC', 'DD', 'EE', 'FF'],
    'Class': ['Apple', 'Apple', 'Pear', 'Orange', 'Pear', 'Orange'],
    'A': [1, 2, 7, 8, 10, 20],
    'B': [2, 8, 9, 9, 8, 12],
    'C': [4, 9, 10, 0, 2, 3]
}

df = pd.DataFrame(data)

# Group by Class and sum the numeric columns
summary_df = df.groupby('Class')[['A', 'B', 'C']].sum().reset_index()

# Print or export the result
print(summary_df)

Running this code will output:

Class   A   B   C
0   Apple   3  10  13
1  Orange  28  21   3
2    Pear  17  15  12

3. SQL (For Database-Stored Data) #

If your data lives in a SQL database, use this query to group and sum:

SELECT 
    Class,
    SUM(A) AS A,
    SUM(B) AS B,
    SUM(C) AS C
FROM your_table_name
GROUP BY Class
ORDER BY Class;

Just replace your_table_name with the actual name of your table, and this will return the aggregated results.

All three methods will give you exactly the output you’re looking for. Pick the one that fits your workflow best!

内容的提问来源于stack exchange，提问作者Lennon Lee