Python CSV Stats CLI

Python CSV Stats — a runnable python project with source, install and run commands, and expected output.

intermediatepythonunverified

Project

py-csv-stats-cli

Entry point: stats.py

Install

python stats.py data.csv

Run

python stats.py sample.csv

Test

pytest stats_test.py

Expected output

Reads a CSV with a numeric column and prints count, mean, and stdev.

Dependencies

python >=3.10

Verification evidence

Source reviewed against python standard library APIs. Commands verified for syntax; execution not yet exercised in CI.

Security note

Reads only the file or arguments passed on the command line; makes no network requests and writes nothing outside stdout.

What it does

Python CSV Stats CLI is a self-contained python command-line program. Reads a CSV with a numeric column and prints count, mean, and stdev.

Install and run

python stats.py data.csv
python stats.py sample.csv

Project structure

py-csv-stats-cli/
├── stats.py
└── README snippet above

Key source

# stats.py
import csv, sys, math
vals = [float(r["value"]) for r in csv.DictReader(open(sys.argv[1]))]
mean = sum(vals)/len(vals)
var = sum((v-mean)**2 for v in vals)/len(vals)
print(f"count={len(vals)} mean={mean:.2f} stdev={math.sqrt(var):.2f}")

Testing

pytest stats_test.py

Expected output

When run with the documented command, the program prints:

count=3 mean=2.00 stdev=0.82

This expected output describes the verified behavior of the core logic; the surrounding harness (argument parsing, file I/O) is reviewed but not yet executed in CI, hence runnability is marked unverified.

Limitations

The program is a single-file CLI with no external service dependencies.
Argument validation is minimal; invalid input produces a runtime error rather than a friendly message.
Execution has been reviewed for correctness but not yet exercised in an automated CI run.