Introduction
The data_fetcher.py
script is the backbone of data acquisition within the G.O.D Framework. It automates the retrieval,
processing, and preparation of data from various sources such as APIs, databases, files, and external systems. It ensures consistency
and scalability in data ingestion.
Purpose
This module serves the following purposes:
- Centralizing the process of data retrieval from multiple sources.
- Providing reusable utilities for API calls, data parsing, and data handling.
- Enabling secure and optimized interactions with external systems and APIs.
- Providing error handling and retry mechanisms for unreliable data sources.
Key Features
- Multi-source Compatibility: Fetches data from APIs, databases, files, or streams.
- Data Parsers: Built-in parsers to handle diverse data formats (e.g., JSON, CSV, XML).
- Rate-limiting: Implements throttling for APIs to comply with request limits.
- Error Recovery: Automatic retries and exception handling for robust operations.
- Data Caching: Optionally caches data to reduce redundant fetches and improve performance.
Logic and Implementation
The data_fetcher.py
module abstracts the complexities of fetching data. It supports both synchronous and asynchronous data retrieval. Below is a simplified example of its implementation:
import requests
import logging
import time
from functools import lru_cache
class DataFetcher:
"""
Handles data retrieval from various sources like APIs, databases, and files.
"""
def __init__(self, base_url=None, headers=None):
self.base_url = base_url
self.headers = headers or {"Content-Type": "application/json"}
self.logger = logging.getLogger("DataFetcher")
def fetch_from_api(self, endpoint, params=None, max_retries=3):
"""
Fetches data from a REST API with retry logic.
Args:
endpoint (str): API endpoint to fetch data from.
params (dict): Optional query parameters for the API call.
max_retries (int): Number of retry attempts for failed requests.
Returns:
dict: Parsed response data if the request is successful.
"""
url = f"{self.base_url}{endpoint}"
retries = 0
while retries < max_retries:
try:
self.logger.info(f"Fetching data from API: {url}")
response = requests.get(url, headers=self.headers, params=params, timeout=10)
response.raise_for_status()
return response.json()
except requests.exceptions.RequestException as e:
self.logger.warning(f"Failed to fetch data ({retries + 1}/{max_retries}): {e}")
retries += 1
time.sleep(2 ** retries) # Exponential backoff
self.logger.error(f"Could not fetch data after {max_retries} attempts")
raise Exception("Data fetch failed")
@lru_cache(maxsize=512)
def fetch_with_caching(self, endpoint, params=None):
"""
Fetches data while caching the results to optimize performance.
Args:
endpoint (str): API endpoint to fetch data from.
params (dict): Optional query parameters for the API call.
Returns:
dict: Cached or newly fetched response data.
"""
return self.fetch_from_api(endpoint, params)
# Example usage
if __name__ == "__main__":
fetcher = DataFetcher(base_url="https://api.example.com")
data = fetcher.fetch_from_api("/data", {"query": "example"})
print("Fetched Data:", data)
This implementation demonstrates fetching data via REST APIs with built-in retries, caching, and error handling, making it suitable for high-resilience applications.
Dependencies
- Requests: For HTTP requests to external APIs.
- Logging: For tracking data fetch operations and errors.
- lru_cache: Built-in caching mechanism to optimize repeated fetches.
Integration with the G.O.D Framework
The data_fetcher.py
module integrates seamlessly with the following components:
- ai_pipeline_audit_logger.py: Logs and monitors data retrieval operations within pipelines.
- ai_data_registry.py: Fetches and registers metadata about the retrieved datasets.
- ai_error_tracker.py: Tracks and manages errors encountered during data fetching.
Future Enhancements
- Add support for GraphQL queries and responses.
- Implement asynchronous data fetching using libraries like aiohttp for improved performance.
- Include a GUI or CLI tool for testing and debugging API endpoints.
- Provide direct integration with cloud-based object stores (e.g., AWS S3, Google Cloud Storage).
- Incorporate advanced caching strategies, including distributed caches like Redis.