wandering-emerald-falcon

Session ID

a1b2c3d4-e5f6-7890-abcd-ef1234567890

Working directory /home/you/projects/datatools

Started 2026-01-15T14:23:01.123Z

Ended 2026-01-15T14:24:47.890Z

Messages 5 user / 5 assistant

Tool calls 2

Resume in Claude Code

cd /home/you/projects/datatools

claude --resume a1b2c3d4-e5f6-7890-abcd-ef1234567890

Human14:23:01

I'm getting a ModuleNotFoundError when I run my script. It says No module named 'pandas' but I'm pretty sure I have it in my requirements. Can you help?

🔧Read▼

file_path:

/home/you/projects/datatools/requirements.txt

↩Result: Read▼

numpy==1.26.4
pandas==2.2.0
requests==2.31.0
pytest==7.4.3
python-dotenv==1.0.0

🔧Read▼

file_path:

/home/you/projects/datatools/script.py

↩Result: Read▼

import pandas as pd
import numpy as np
from dotenv import load_dotenv
import os

load_dotenv()

DATA_PATH = os.getenv('DATA_PATH', 'data/input.csv')

def load_data(path: str) -> pd.DataFrame:
    df = pd.read_csv(path)
    print(f'Loaded {len(df)} rows from {path}')
    return df

def summarize(df: pd.DataFrame) -> None:
    print(df.describe())
    print('\nMissing values:')
    print(df.isnull().sum())

if __name__ == '__main__':
    df = load_data(DATA_PATH)
    summarize(df)

Claude14:23:12in:1450 | out:228 tokens

Your requirements.txt does list pandas==2.2.0, so the package is declared correctly. The issue is almost certainly that you're running the script outside of your virtual environment, so Python can't find the installed packages.

Here's how to fix it:

1. Activate your virtual environment first:

# If you're using venv
source .venv/bin/activate

# Or if it's named 'env'
source env/bin/activate

2. If you haven't installed the requirements into the venv yet:

pip install -r requirements.txt

3. Then run your script:

python script.py

You can verify which Python / pip you're using at any point with which python and which pip — they should both point to paths inside your venv directory (e.g. .venv/bin/python), not a system-level path like /usr/bin/python.

If you don't have a venv set up yet, you can create one with:

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Turn duration: 9.6s

Human14:24:05

Oh wow, that was it. I forgot I opened a new terminal tab. It works now. Is there a way to make VS Code activate the venv automatically?

Claude14:24:11in:1680 | out:210 tokens

Yes! VS Code handles this automatically if you configure it correctly.

The easiest way: Open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P), type "Python: Select Interpreter", and choose the Python interpreter inside your .venv folder (it'll show something like .venv/bin/python with the pandas version listed).

Once selected, VS Code will:
- Activate the venv automatically in any new integrated terminal you open (Terminal > New Terminal)
- Use the correct interpreter for linting, IntelliSense, and running files via the play button

To make this stick for the project, VS Code saves the choice in .vscode/settings.json:

{
  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python"
}

You can also commit that file to your repo so teammates automatically get the same interpreter selection.

Note: this only applies to terminals opened *inside* VS Code. If you open an external terminal you'll still need to source .venv/bin/activate manually.

Turn duration: 5.3s

Human14:24:45

Perfect, that worked. Thanks!

Claude14:24:47in:1720 | out:32 tokens

Glad it's working! The "forgot to activate the venv in a new tab" issue catches everyone at some point. Happy coding!

Turn duration: 2.3s