pyjquants 0.1.1

Investor-friendly OOP Python library for J-Quants API

PyJQuants

Investor-friendly OOP Python library for J-Quants API.

Features

• Intuitive OOP design: Stock("7203") just works
• Lazy-loaded attributes: stock.name, stock.prices, stock.financials
• Auto-authentication: Reads credentials from environment variables
• Paper trading simulation: Trader, Order, Portfolio, Position
• Type hints: Full type annotations with Pydantic models
• DataFrame integration: Price data returned as pandas DataFrames

Installation

pip install pyjquants

For development:

pip install pyjquants[dev]

Quick Start

Setup

Set your J-Quants credentials as environment variables:

export JQUANTS_MAIL_ADDRESS="[e-mail]"
export JQUANTS_PASSWORD="your_password"

Basic Usage

import pyjquants as pjq

# Create a stock - data is lazy-loaded from API
stock = pjq.Stock("7203")  # Toyota

# Access attributes (fetched on first access, then cached)
stock.code              # "7203"
stock.name              # "トヨタ自動車"
stock.name_english      # "Toyota Motor Corporation"
stock.sector_33.name    # "輸送用機器"
stock.market_segment    # MarketSegment.TSE_PRIME

# Get price data as DataFrame
stock.prices            # Recent 30 trading days
stock.adjusted_prices   # Adjusted for splits/dividends

# Custom date range
from datetime import date
stock.prices_between(date(2024, 1, 1), date(2024, 6, 30))

# Financial data
stock.financials        # Latest financial statements
stock.dividends         # Dividend history

Paper Trading

import pyjquants as pjq
from datetime import date
from decimal import Decimal

# Initialize trader with starting cash
trader = pjq.Trader(initial_cash=10_000_000)

# Get stock
toyota = pjq.Stock("7203")

# Place orders
order = trader.buy(toyota, 100)                    # Market buy 100 shares
order = trader.buy(toyota, 100, price=2500)        # Limit buy at 2500
order = trader.sell(toyota, 50)                    # Market sell

# Simulate fills using historical prices
executions = trader.simulate_fills(date(2024, 6, 15))

# Check portfolio
trader.cash                     # Current cash balance
trader.portfolio.total_value    # Total portfolio value
trader.portfolio.positions      # List of positions
trader.portfolio.realized_pnl   # Realized P&L
trader.portfolio.unrealized_pnl # Unrealized P&L

# Get position for a specific stock
position = trader.position(toyota)
if position:
    print(f"Holding {position.quantity} shares")
    print(f"Average cost: {position.average_cost}")
    print(f"Unrealized P&L: {position.unrealized_pnl}")

Market Data

import pyjquants as pjq
from datetime import date

# Market utilities
market = pjq.Market()
market.is_trading_day(date(2024, 12, 25))  # False
market.trading_days(date(2024, 1, 1), date(2024, 1, 31))
market.next_trading_day(date(2024, 1, 1))

# Sector information
market.sectors_17  # 17-sector classification
market.sectors_33  # 33-sector classification

Index Data

import pyjquants as pjq

# Get TOPIX index
topix = pjq.Index.topix()
topix.name      # "TOPIX"
topix.prices    # Recent 30 days

# All available indices
indices = pjq.Index.all()

Universe Filtering

import pyjquants as pjq

# Get all stocks and filter
universe = pjq.Universe.all()
prime_stocks = (universe
    .filter_by_market(pjq.MarketSegment.TSE_PRIME)
    .head(50))

# Get prices for filtered universe
prime_stocks.prices  # Multi-stock DataFrame

Configuration

Environment Variables

Variable	Description
JQUANTS_MAIL_ADDRESS	Your J-Quants email
JQUANTS_PASSWORD	Your J-Quants password
JQUANTS_REFRESH_TOKEN	(Optional) Refresh token
JQUANTS_CACHE_ENABLED	Enable caching (default: true)
JQUANTS_CACHE_TTL	Cache TTL in seconds (default: 3600)
JQUANTS_RATE_LIMIT	Requests per minute (default: 60)

TOML Configuration

Create ~/.jquants/config.toml:

[credentials]
mail_address = "[e-mail]"
password = "your_password"

[cache]
enabled = true
ttl_seconds = 3600

[rate_limit]
requests_per_minute = 60

Data Models

PriceBar

from pyjquants import PriceBar

bar = stock.latest_price
bar.date            # datetime.date
bar.open            # Decimal
bar.high            # Decimal
bar.low             # Decimal
bar.close           # Decimal
bar.volume          # int
bar.adjustment_factor  # Decimal
bar.adjusted_close  # Decimal (adjusted for splits)

Order

from pyjquants import Order, OrderSide, OrderType, OrderStatus

order = Order.market_buy(stock, 100)
order = Order.limit_sell(stock, 100, Decimal("2600"))

order.id            # Unique order ID
order.side          # OrderSide.BUY or OrderSide.SELL
order.order_type    # OrderType.MARKET or OrderType.LIMIT
order.status        # OrderStatus.PENDING, FILLED, CANCELLED, etc.
order.is_active     # True if pending/partially filled
order.is_filled     # True if fully filled

API Reference

Entities

Class	Description
Stock(code)	Japanese stock with lazy-loaded data
Index	Market index (TOPIX, etc.)
Market	Market utilities (calendar, sectors)
Universe	Filterable collection of stocks

Trading

Class	Description
Trader	Paper trading interface
Order	Buy/sell order
Portfolio	Holdings and cash
Position	Single stock holding
Execution	Filled order record

Enums

Enum	Values
MarketSegment	TSE_PRIME, TSE_STANDARD, TSE_GROWTH, OTHER
OrderSide	BUY, SELL
OrderType	MARKET, LIMIT
OrderStatus	PENDING, FILLED, PARTIALLY_FILLED, CANCELLED, REJECTED

Development

# Clone repository
git clone https://github.com/obichan117/pyjquants.git
cd pyjquants

# Install with dev dependencies
pip install -e ".[dev]"

# Run tests
pytest tests/ -v

# Run tests with coverage
pytest tests/ --cov=pyjquants --cov-report=term-missing

# Type checking
mypy pyjquants/

# Linting
ruff check pyjquants/

License

MIT License - see LICENSE for details.

Links

• J-Quants API Documentation
• GitHub Repository