Karim shoair
77 lines
5.6 KiB
Markdown
77 lines
5.6 KiB
Markdown
## Introduction
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Fetchers are classes that can do requests or fetch pages for you easily in a single-line fashion with many features and then return a [Response](#response-object) object.
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This feature was introduced because the only option before v0.2 was to fetch the page as you wanted, then pass it manually to the `Adaptor` class and start playing with it.
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> Fetchers are not wrappers built on top of other libraries, but they use these libraries as an engine to make requests/fetch pages easily for you while fully utilizing that engine and adding features for you that aren't included in those engines
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## Fetchers Overview
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Scrapling provides three different fetcher classes, each designed for specific use cases.
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The following table compares them and can be quickly used for guidance.
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| Feature | Fetcher | PlayWrightFetcher | StealthyFetcher |
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|--------------------|----------------|--------------------------------------------------------------------------------|--------------------------------------------------------------------------------------|
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| Relative speed | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐ |
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| Stealth | ⭐ | ⭐⭐ | ⭐⭐⭐⭐ |
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| Anti-Bot options | ⭐ | ⭐⭐ | ⭐⭐⭐⭐ |
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| JavaScript loading | ❌ | ✅ | ✅ |
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| Memory Usage | ⭐ | ⭐⭐⭐ | ⭐⭐⭐ |
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| Best used for | Basic scraping | - Dynamically loaded websites <br/>- Small automation<br/>- Slight protections | - Dynamically loaded websites <br/>- Small automation <br/>- Complicated protections |
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| Browser(s) | ❌ | Chromium and Google Chrome | Modified Firefox |
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| Browser API used | ❌ | PlayWright | PlayWright |
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| Setup Complexity | Simple | Simple | Simple |
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In the following pages, we will talk about each one in detail.
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## Parser configuration in all fetchers
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All fetchers classes share the same import, as you will see in the upcoming pages
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```python
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>>> from scrapling.fetchers import Fetcher, AsyncFetcher, StealthyFetcher, PlayWrightFetcher
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```
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Then you use it right away without initializing like this, and it will use the default parser settings:
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```python
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>>> page = StealthyFetcher.fetch('https://example.com')
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```
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If you want to configure the parser ([Adaptor class](../parsing/main_classes.md#adaptor)) that will be used on the response before returning it for you, then do this first:
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```python
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>>> from scrapling.fetchers import Fetcher
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>>> Fetcher.configure(auto_match=True, encoding="utf8", keep_comments=False, keep_cdata=False) # and the rest
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```
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or
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```python
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>>> from scrapling.fetchers import Fetcher
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>>> Fetcher.auto_match=True
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>>> Fetcher.encoding="utf8"
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>>> Fetcher.keep_comments=False
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>>> Fetcher.keep_cdata=False # and the rest
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```
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Then, continue your code as usual.
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The available configuration arguments are: `auto_match`, `huge_tree`, `keep_comments`, `keep_cdata`, `storage`, and `storage_args`, which are the same ones you give to the `Adaptor` class. You can display the current configuration anytime by running `<fetcher_class>.display_config()`.
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> Note: The `auto_match` argument is disabled by default; you must enable it to use that feature.
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### Set parser config per request
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As you probably understood, the logic above for setting the parser config will work globally for all requests/fetches done through that class, and it's intended for simplicity.
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If your use case requires a different configuration for each request/fetch, you can pass a dictionary to the request method (`fetch`/`get`/`post`/...) to an argument named `custom_config`.
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## Response Object
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The `Response` object is the same as the [Adaptor](../parsing/main_classes.md#adaptor) class, but it has added details about the response like response headers, status, cookies, etc... as shown below:
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```python
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>>> from scrapling.fetchers import Fetcher
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>>> page = Fetcher.get('https://example.com')
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>>> page.status # HTTP status code
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>>> page.reason # Status message
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>>> page.cookies # Response cookies as a dictionary
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>>> page.headers # Response headers
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>>> page.request_headers # Request headers
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>>> page.history # Response history of redirections, if any
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>>> page.body # Raw response body
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>>> page.encoding # Response encoding
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```
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All fetchers return the `Response` object. |