esuls 0.2.1

Utility library for async database operations, HTTP requests, and parallel execution

esuls

A Python utility library for async database operations, HTTP requests, and parallel execution utilities.

Features

• AsyncDB - Type-safe async SQLite with dataclass schemas
• Async HTTP client - High-performance HTTP client with retry logic and connection pooling
• Parallel utilities - Async parallel execution with concurrency control
• CloudFlare bypass - curl-cffi integration for bypassing protections

Installation

# With pip
pip install esuls

# With uv
uv pip install esuls

Usage

Parallel Execution

import asyncio
from esuls import run_parallel

async def fetch_data(id):
    await asyncio.sleep(1)
    return f"Data {id}"

async def main():
    # Run multiple async functions in parallel with concurrency limit
    results = await run_parallel(
        lambda: fetch_data(1),
        lambda: fetch_data(2),
        lambda: fetch_data(3),
        limit=20  # Max concurrent tasks
    )
    print(results)

asyncio.run(main())

Database Client (AsyncDB)

Built on SQLAlchemy 2.0 Core async. Dataclass-as-schema ergonomics; SQLite behind the scenes with a tuned PRAGMA set (WAL, foreign_keys=ON, mmap_size, temp_store=MEMORY, wal_autocheckpoint, busy_timeout=30s). Two engines per db: a StaticPool writer (single conn, serialised by an in-process write lock) and a 4-conn reader pool for concurrent WAL reads.

import asyncio
from dataclasses import dataclass, field
from esuls import AsyncDB, BaseModel

@dataclass
class User(BaseModel):                          # id + created_at + updated_at, all UTC
    name: str = field(default="", metadata={"index": True})
    email: str = field(default="", metadata={"unique": True})
    age: int = 0

async def main():
    db = AsyncDB("users.db", "users", User)

    # Single upsert (idempotent by primary key).
    await db.save(User(name="Alice", email="[e-mail]", age=30))

    # Atomic batch — one round-trip, fail-fast on any bad item.
    await db.save_batch([
        User(name="Bob",     email="[e-mail]",     age=25),
        User(name="Charlie", email="[e-mail]", age=35),
    ])

    # Best-effort batch — per-item loop, log+skip rotten items.
    await db.save_each([User(name="x", email=""), User(name="y", email="[e-mail]")])

    # Queries.
    results = await db.find(name="Alice")
    adults  = await db.find(age__gte=18, order_by="-age")
    count   = await db.count(age__gte=18)
    user    = await db.get_by_id("some-uuid")

    # Bulk updates / deletes (both require at least one filter).
    n = await db.update_many({"status": "verified"}, email__like="[e-mail]")
    n = await db.delete_many(age__lt=18)

    # Aggregations: count / count_distinct / sum / avg / min / max + GROUP BY + HAVING.
    by_age = await db.aggregate(
        group_by="age",
        count=True, count_distinct="email",
        having={"count__gte": 2},
        order_by="-count",
    )

    # Stream big result sets without materialising in memory.
    async for u in db.stream(order_by="created_at", batch_size=500):
        process(u)

    # Project specific columns (returns List[dict], not List[User]).
    rows = await db.find_columns(["id", "email"], age__gte=18)

    # Always close: PRAGMA optimize + wal_checkpoint(TRUNCATE) on exit.
    await db.close()

asyncio.run(main())

Query operators (suffix on filter kwargs, e.g. age__gte=18):

• eq (default), neq, gt, gte, lt, lte
• like — SQL LIKE
• in, not_in — pass any iterable
• is_null=True/False, not_null=True/False
• between=(lo, hi) — inclusive

HAVING in aggregate() accepts the same suffixes — but on alias names (count, count_distinct_<col>, sum_<col>, …), not raw columns.

Schema base classes

Pick the base class that matches the table's needs:

Base	Primary key	Timestamps	Use for
IdModel	str (UUID4)	—	Cache / lookup tables — no created_at/updated_at columns
IntIdModel	int autoincrement	—	High-throughput tables where UUID string PK fragments the B-tree
TimestampedModel	str (UUID4)	created_at + updated_at (UTC)	The default — same as BaseModel alias
TimestampedIntModel	int autoincrement	created_at + updated_at (UTC)	Combines int PK perf + auto-managed timestamps

BaseModel is a backward-compat alias for TimestampedModel. Timestamps use the public utcnow() clock (always timezone-aware UTC).

File-based migrations

Drop NNN_*.py scripts next to the db file under migrations/. Each exports version, description, and async def upgrade(conn):

# my_app/migrations/001_add_email_index.py
from sqlalchemy import text

version = 1
description = "Index users.email for login lookup"

async def upgrade(conn):
    await conn.execute(text("CREATE INDEX idx_users_email ON users(email)"))

AsyncDB picks them up on first use, applies pending ones inside the same transaction as schema init (atomic), and stamps PRAGMA user_version. Fresh databases leap-frog to the latest version (the dataclass already represents the post-migration state). Migrations are forward-only.

# Inspect without opening a db:
from esuls import discover_migrations
print(discover_migrations(Path("my_app/migrations")))

# Inspect with applied/pending status:
db = AsyncDB(...)
print(await db.list_migrations())

Concurrency model

• Writes serialise through a per-loop, per-db-path asyncio.Lock + a single physical writer connection. No SQLITE_BUSY surfaces to the caller; transient contention is retried with exponential backoff (jittered) up to max_retries (configurable per call).
• Reads use a 4-conn pool — true concurrent reads under WAL.
• Cross-loop reuse is supported: the same AsyncDB instance survives multiple asyncio.run() calls because locks/engines are keyed on the running loop.
• await db.close() (or async with AsyncDB(...)) is required for clean fd release. Skipping it emits a ResourceWarning when the engines are GC'd; aiosqlite's worker thread is daemon-marked so the process never hangs on missing close.

HTTP Request Client

import asyncio
from esuls import AsyncRequest, make_request

# Using context manager (recommended for multiple requests)
async def example1():
    async with AsyncRequest() as client:
        response = await client.request(
            url="https://api.example.com/data",
            method="GET",
            add_user_agent=True,
            max_attempt=3,
            timeout_request=30
        )
        if response:
            data = response.json()
            print(data)

# Using standalone function (uses shared connection pool)
async def example2():
    response = await make_request(
        url="https://api.example.com/users",
        method="POST",
        json_data={"name": "Alice", "email": "[e-mail]"},
        headers={"Authorization": "Bearer token"},
        max_attempt=5,
        force_response=True  # Return response even on error
    )
    if response:
        print(response.status_code)
        print(response.text)

asyncio.run(example1())

Request Parameters:

• url - Request URL
• method - HTTP method (GET, POST, PUT, DELETE, etc.)
• headers - Request headers
• cookies - Cookies dict
• params - URL parameters
• json_data - JSON body
• files - Multipart file upload
• proxy - Proxy URL
• timeout_request - Timeout in seconds (default: 60)
• max_attempt - Max retry attempts (default: 10)
• force_response - Return response even on error (default: False)
• json_response - Validate JSON response (default: False)
• json_response_check - Check for key in JSON response
• skip_response - Skip if text contains pattern(s)
• exception_sleep - Delay between retries in seconds (default: 10)
• add_user_agent - Add random User-Agent header (default: False)

CloudFlare Bypass

import asyncio
from esuls import make_request_cffi

async def fetch_protected_page():
    html = await make_request_cffi("https://protected-site.com")
    if html:
        print(html)

asyncio.run(fetch_protected_page())

Development

Project Structure

utils/
├── pyproject.toml
├── README.md
├── LICENSE
└── src/
    └── esuls/
        ├── __init__.py
        ├── utils.py          # Parallel execution utilities
        ├── db_cli.py         # AsyncDB with dataclass schemas
        └── request_cli.py    # Async HTTP client

Local Development Installation

# Navigate to the project
cd utils

# Install in editable mode with uv
uv pip install -e .

# Or with pip
pip install -e .

Building and Publishing

# With uv
uv build && twine upload dist/*

# Or with traditional tools
pip install build twine
python -m build
twine upload dist/*

Advanced Features

AsyncDB Schema Definition

from dataclasses import dataclass, field
from esuls import BaseModel
from datetime import datetime
from typing import Optional, List
import enum

class Status(enum.Enum):
    ACTIVE = "active"
    INACTIVE = "inactive"

@dataclass
class User(BaseModel):
    # BaseModel provides: id, created_at, updated_at

    # Indexed field
    email: str = field(metadata={"index": True, "unique": True})

    # Simple fields
    name: str = ""
    age: int = 0

    # Enum support
    status: Status = Status.ACTIVE

    # JSON-serialized complex types
    tags: List[str] = field(default_factory=list)

    # Optional fields
    phone: Optional[str] = None

    # Table constraints (optional)
    __table_constraints__ = [
        "CHECK (age >= 0)"
    ]

Connection Pooling & Performance

The HTTP client uses:

• Shared connection pool (prevents "too many open files" errors)
• Automatic retry with exponential backoff
• SSL optimization
• Random User-Agent rotation
• Cookie and header persistence

License

MIT License