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name: excel-weighted-growth-calculator description: When the user requests to calculate year-over-year growth rates for business segments using a weighted methodology from Excel files, particularly when there's a mapping sheet defining segment-to-source weights and a raw data sheet with time-series values. This skill handles reading Excel workbooks with multiple sheets, parsing segment/source mappings, calculating YoY growth rates for sources, applying weighted sums to compute segment growth rates, handling missing data with N/A values, and outputting results to a new Excel file with proper formatting.

Instructions

Overview

This skill calculates year-over-year (YoY) growth rates for business segments based on a weighted methodology defined in an Excel workbook. It reads two key sheets:

1. Methodology Sheet: Contains segment-to-source weight mappings.
2. RawData Sheet: Contains time-series data for each source.

The skill outputs a new Excel file with segment growth rates for specified years.

Core Workflow

1. Parse Input Requirements

• Identify the input Excel file path (e.g., Market_Data.xlsx).
• Determine the output file name (e.g., segment_growth_rates.xlsx).
• Confirm the year range for calculations (e.g., 2015-2024).
• Note any special instructions (e.g., exclude "Total" segment, maintain column order).

2. Extract Methodology Mappings

• Read the Methodology sheet.
• Identify source names from the header row (typically row 2, columns C-Q).
• Identify segment names from column B (rows 4-13, excluding "Total").
• For each segment, extract non-zero weights mapping to sources.
• Preserve the segment order as they appear in the sheet.

3. Extract Raw Data

• Read the RawData sheet.
• Identify source names from the header row (typically row 4, columns B-P).
• Map each source to its data column.
• Extract year values from column A and map to row numbers.
• For each source and year, read the value. Treat formula cells (strings starting with '=') as None/null.

4. Calculate Source Growth Rates

• For each source, for each target year (e.g., 2015-2024):
  • Get the current year value and the previous year value.
  • If either value is None or previous year is 0, growth rate is None.
  • Otherwise, calculate: ((current - previous) / previous) * 100.
• Store results in a nested dictionary: source_growth_rates[source][year].

5. Calculate Segment Growth Rates

• For each segment, for each target year:
  • Retrieve the segment's weight mapping from methodology.
  • For each source in the mapping:
    • Get the source's growth rate for that year.
    • If any source's growth rate is None, mark the entire segment's growth as "N/A" for that year.
    • Otherwise, compute the weighted sum: sum(weight * growth_rate).
  • Round the result to one decimal place.
• Store results: segment_growth_rates[segment][year].

6. Generate Output Excel File

• Create a new workbook.
• Write header row: First column "Year", followed by segment names in the preserved order.
• For each target year, write a row: year value followed by each segment's growth rate (number or "N/A").
• Save the file to the specified output path.

7. Validate Output

• Verify the file was created successfully.
• Optionally, read back and display a sample to confirm formatting.

Key Considerations

• Missing Data: If a source has no data for current or previous year, its growth is None. If any source in a segment's mapping has None growth, the segment's growth is "N/A".
• Formula Cells: Treat cells with formulas (text starting with '=') as null/unavailable.
• Segment Order: Maintain the exact segment order as they appear in the Methodology sheet rows.
• Output Format: First column is "Year", subsequent columns are segment names. Growth rates are percentages rounded to one decimal place or "N/A".

Error Handling

• If the input file or sheets are missing, notify the user.
• If source names between Methodology and RawData sheets don't align, attempt fuzzy matching or notify.
• If year range extends beyond available data, calculate only for available years.

Usage Example

User Request: "Based on the provided file Market_Data.xlsx, calculate the year-over-year growth rate percentage for each segment from 2015 to 2024 according to the segment/source mapping provided in the Methodology sheet (rounded to one decimal place), and save the results to a new Excel file named segment_growth_rates.xlsx where the first column is Year and the subsequent columns are the exact names (excluding Total) of segments arranged in the same order as they appear in rows in the Methodology sheet."

Skill Execution:

1. Parse request to identify input file, output name, year range.
2. Execute the workflow above using the bundled script.
3. Deliver the output file.