anthropics/financial-services · error · ImportError

openpyxl not installed. Run: pip install openpyxl

Error message

openpyxl not installed. Run: pip install openpyxl

What it means

Raised in DCFModelValidator.__init__ of the vertical-plugins (financial-analysis) source copy of validate_dcf.py when openpyxl cannot be imported. openpyxl is what loads the workbook twice (data_only=False for formulas, data_only=True for cached values), so the constructor fails fast with an actionable install message instead of a raw ImportError.

Source

Thrown at plugins/vertical-plugins/financial-analysis/skills/dcf-model/scripts/validate_dcf.py:20

"""
DCF Model Validation Script
Validates Excel DCF models for formula errors and common DCF mistakes
"""

import sys
import json
from pathlib import Path
from typing import Optional


class DCFModelValidator:
    """Validates DCF models for errors and quality issues"""

    def __init__(self, excel_path: str):
        try:
            import openpyxl
        except ImportError:
            raise ImportError("openpyxl not installed. Run: pip install openpyxl")

        self.excel_path = excel_path
        self.openpyxl = openpyxl

        if not Path(excel_path).exists():
            raise FileNotFoundError(f"File not found: {excel_path}")

        self.workbook_formulas = openpyxl.load_workbook(excel_path, data_only=False)
        self.workbook_values = openpyxl.load_workbook(excel_path, data_only=True)
        self.errors = []
        self.warnings = []
        self.info = []
        
    def validate_all(self) -> dict:
        """
        Run all validation checks

        Returns:

View on GitHub (pinned to 69cbc81467)

Solutions

1. Install into the running interpreter: python -m pip install openpyxl
2. Install the skill's requirements if shipped: python -m pip install -r skills/dcf-model/scripts/requirements.txt
3. Sanity check: python -c 'import openpyxl; print(openpyxl.__version__)'; if it fails, fix the interpreter/venv mismatch
4. Add openpyxl to the runtime provisioning for the financial-analysis skill (image, setup script, or SKILL.md install step)

Example fix

# before
python skills/dcf-model/scripts/validate_dcf.py model.xlsx
# ImportError: openpyxl not installed. Run: pip install openpyxl

# after
python -m pip install openpyxl
python skills/dcf-model/scripts/validate_dcf.py model.xlsx

import importlib.util
if importlib.util.find_spec('openpyxl') is None:
    raise SystemExit('openpyxl missing: python -m pip install openpyxl')

def has_openpyxl() -> bool:
    return importlib.util.find_spec('openpyxl') is not None

try:
    validator = DCFModelValidator(path)
except ImportError as e:
    raise SystemExit(f'Dependency error: {e}. Install with: python -m pip install openpyxl')

When it happens

Trigger: Instantiating DCFModelValidator(excel_path) under an interpreter lacking openpyxl — e.g. running the financial-analysis skill script with system Python, in CI, or in a container without the package. The try: import openpyxl at the top of __init__ fails and re-raises with this message.

Common situations: Minimal Docker/agent-sandbox images; pip installing into a different Python than the one executing the script; venv/conda not activated; freshly cloned repo where dependencies were never installed; Python version upgrades losing site-packages.

Related errors

• openpyxl not installed. Run: pip install openpyxl
• openpyxl not installed. Run: pip install openpyxl
• File not found: {excel_path}
• File not found: {excel_path}
• File not found: {excel_path}

AI-assisted analysis of anthropics/financial-services@69cbc81467 (2026-08-27). Data as JSON: /api/errors/a526d6fce84fb0b3. Report an issue: GitHub.