Open-Interest-Data-Extractor

Fetches the NIFTY & BANKNIFTY option chain from the NSE India website and displays Open Interest in a colour-coded console table.

Setup

pip install requests

VPN users: NSE blocks requests from non-Indian IPs. Disable your VPN before running, or use an Indian exit node.

Usage

python main.py                  # both indices, table output
python main.py -s nifty         # NIFTY only
python main.py -s banknifty     # BANKNIFTY only
python main.py -n 8             # 8 strikes above/below ATM (overrides default)
python main.py --json           # raw JSON output (pipe to jq, etc.)
python main.py --json --pretty  # indented JSON
python main.py --no-color       # plain text, no ANSI codes
python main.py --help           # full flag reference

CLI flags

Flag	Default	Description
-s, --symbol	both	Index to fetch: nifty, banknifty, or both
-n, --strikes	per-index	Number of strikes above/below ATM (Nifty: 5, BNF: 10)
--json	off	Output raw JSON instead of the coloured table
--pretty	off	Indent JSON output (only with --json)
--no-color	off	Strip ANSI colour codes from terminal output

Example: pipe JSON into another tool

python main.py -s nifty --json --pretty | jq '.data[0].rows[:3]'
python main.py --json | python -c "
import sys, json
data = json.load(sys.stdin)
for idx in data['data']:
    print(idx['symbol'], sum(r['ce_oi'] + r['pe_oi'] for r in idx['rows']))
"

What's Changed

This branch addresses the original TODOs and a few bugs:

Fix	Description
✅ Cookie jar bug	Removed the unused manual cookies dict that shadowed the global — requests.Session() now handles cookies automatically.
✅ 401 retry	Retries the correct URL when a session expires, not a hardcoded NIFTY URL.
✅ Error handling	Network errors, HTTP failures, and bad JSON are caught and reported instead of crashing.
✅ Code structure	Data fetching (fetch_json) is separated from display (print_oi_table), making the code testable and reusable.
✅ Colour helpers	Replaced 10 near-identical functions with a 3-line dict + single c() function.
✅ if __name__ guard	The script can now be imported without executing.
✅ Globals declared	Module-level variables are explicitly declared.
✅ OI formatting	Values now display with comma separators (e.g., 123,456).
✅ Named constants	num_strikes=5, step=50 are keyword arguments instead of magic numbers.
✅ CLI arguments	--symbol, --strikes, --json, --pretty, --no-color via argparse.
✅ JSON output	--json flag dumps raw option-chain data as JSON for pipelines.

Credits

Inspired by VarunS2002's Python-NSE-Option-Chain-Analyzer.