Web Scraping, Data Mining

How Multi-Processing Powers True Parallel Execution In the world of automation and software development, performance optimization is of prime importance. Be it constructing a high-performance data scraper, executing a massive simulation, or designing a real-time application, knowing what’s going on behind the curtains in terms of how your program executes tasks can be the difference maker. That is where principles such as multi-threading, multi-processing, and multi-tasking come into action. In this article, our research team at Scraping Solution will demystify what each of these terms is, contrast their pros and cons, and identify the best tools and agents for dealing with concurrent or parallel execution in contemporary programming. 1.Multi-Threading A single process executes many threads in the same memory area, enabling simultaneous execution.  Types:Preemptive: The OS manages task switching (e.g., Windows, Linux).Cooperative: Voluntarily yielding control (older systems). Key Features Multiple threads occupy the same memory space. Lightweight and quicker to switch between threads. Ideal for I/O-bound operations such as network calls, file I/O, or scraping services. Pros and Cons of Multi-Threading: Multi-threading is more efficient in context switching. That enables effective use of memory. It is perfect for non-blocking, lightweight operations. While on the other hand, it is prone to race conditions and deadlocks. Also, it is not suitable for CPU-bound tasks as there is the Global Interpreter Lock (GIL) in Python. 2.Multi-Processing Multi-processing refers to multiple processes running simultaneously. Every process contains its own memory area, which prevents GIL constraints and enables true parallelism. Key Features: Every process is executed in its own memory space. Suited for CPU-intensive tasks such as intense computation or image processing. Supports real parallel execution on multi-core CPUs. Pros and Cons of Multi-Processing Multi-Processing has a plus point as it avoids Python’s GIL. It is more robust for long or intensive processes. The main advantage is that it crashes in a single process without impacting on the other processes. Drawbacks of Multi-Processing includes the higher use of memory. It takes a lot more time to begin and exchange information between processes (through pipes or queues). 3.Multi-Tasking Multi-tasking is the general idea of running several tasks simultaneously. It can be carried out through multi-threading, multi-processing, or asynchronous programming. Types: Preemptive Multi-tasking (OS-level): CPU time is allocated by the system to tasks. Cooperative Multi-tasking (App-level): Tasks give up control voluntarily. Pros and Cons of Multi-Tasking:Multi-tasking is ideal for OS-level task management, and basic background processes. It enhances system utilization along with enriching responsiveness for several users or tasks. The major disadvantage of multi-tasking is that it needs proper resource management to prevent performance problems. The best parallel processing libraries for Python Multi-Processing Libraries multiprocessing (Python Standard Library): The multiprocessing module enables you to execute independent processes rather than threads. A separate memory space is available for each process, and thus it does not suffer from Python’s Global Interpreter Lock (GIL) and delivers real parallelism. Key Features: Runs multiple tasks on several CPU cores. Ideal for CPU-intensive tasks (intensive calculations, image processing, etc.). Processes don’t share memory — communication through Queue, Pipe, or Manager. Ray: A basic distributed runtime and a set of AI libraries to help streamline machine learning computation workloads are provided by the Ray library, a homogenous foundation for scaling Python and AI applications. offloads and parallelizes workloads related to AI and machine learning onto CPUs, computers, and GPUs. Dask: Outside in, Dask looks a lot like Ray. With an integrated task scheduling system, support for Python data frameworks like NumPy, and the ability to expand from one machine to several, it is also a Python library for distributed parallel computing. One of the major differences between Dask and Ray is the scheduler. Dask has a centralized scheduler that processes all tasks for a cluster. Ray is decentralized, with each machine having its own scheduler, so any problems with a scheduled task are resolved at the level of the individual machine, not the entire cluster. Dispy: Dispy is a Python library for distributed and parallel computing that allows computations to be executed in parallel across several processors within one machine or across many machines in a cluster, grid, or cloud.It is especially appropriate for data-parallel (SIMD) paradigms in which a computation is called with various large sets of data separately. Pandaral·lel: The pandarallel library is a Python utility aimed at accelerating computation by parallelizing operations across several CPUs while using pandas. The library makes it possible for users to parallelize their pandas’ operations with just a one-line change in code, which can effectively cut computation time for large datasets. Ipyparallel: Based on the Jupyter protocol, the IPython Parallel (ipyparallel) library is a Python package and collection of CLI scripts for controlling groups of IPython processes. Ipyparallel supports many ways of doing parallel execution, such as the use of map to apply functions to sequences and dividing the workload evenly between accessible nodes. Also, it offers decorators to functions to run remotely or parallel always. Joblib: Joblib has two principal objectives: execute jobs in parallel, and don’t recalculate results if nothing has changed. These optimizations make Joblib a good fit for scientific computing, where reproducible results are holy. It is meant to support lightweight pipelining so that developers don’t have to parallelize operations and speed calculations, especially for computationally expensive tasks. Parsl: Python’s Parse library is meant to make text parsing simpler using the same syntax form as Python’s format() so that it becomes easier to learn and work with compared to the use of regular expressions. It is especially handy for extracting data from text, like parsing phone numbers, dealing with time text, and processing HTML tags Using instructions to the shell, Parsl enables you to run not just native Python programs but also any external software. Celery: Celery is an open-source library for Python asynchronous task queues that are centered on real-time processing and task scheduling. It is programmed to run tasks simultaneously on one or more worker nodes with multiprocessing, eventlet, or gevent. Multi-Threading Libraries Python’s Threading Library Python’s threading library is ideal for I/O-bound tasks, that are effective in processing multiple network requests. It does not use multiple CPU cores but assists in quicker execution. futures.ThreadPoolExecutor: It simplifies working with a pool of threads, async execution, and getting results cleanly. Its key features include Thread pooling built-in – no need to manually deal with threads. Provides clean, readable syntax with.submit() and.map(). Scrapy: Scrapy is a high-performance, open-source Python web crawling and scraping framework. For businesses needing professional web scraping services, this approach ensures scalability. Unlike threading or multiprocessing in traditional programming, Scrapy employs an asynchronous networking engine to manage multiple requests at once without creating multiple threads or processes. Key Concurrency Features: Executes non-blocking HTTP requests. Single-threaded, event-driven architecture. Use Twisted to deal with many requests at once. Optimized for I/O-bound operations (such as waiting on server responses). Multi-Tasking Libraries Asyncio: asyncio