In a python crawler, when you send an HTTP request to the target, you usually get a response object. This object contains the server's response, such as status code, response header, response body, etc. Processing response objects typically involves the following steps:
Check the status code: First, you need to check the status code of the HTTP response. A status code is a three-digit number that indicates the result of a request. Common status codes are 200 (Successful (not found), etc.
python
Copy. import requests
response = requests.get('')
if response.status_code == 200:
print('The request was successful')
else:print('The request failed with status code:', response.status_code)
Parsing the response body: The response body usually contains the HTML content of the web page or other formatted data. You need to parse the response body according to the data format of the target. Common parsing methods include regular expressions, beautifulsoup, lxml, etc.
python
Copy. from bs4 import beautifulsoup
soup = beautifulsoup(response.text, 'html.parser')
Now you can use the beautifulsoup object to extract data from a web page.
Handling exceptions: In a crawler, you may encounter various exceptions such as network issues, server errors, etc. To ensure the stability of the program, you should use try....except statement to handle these exceptions.
python
Copy. try:
response = requests.get('')
response.Raise for status() If the status code is not 2xx, an HTTPError exception will be thrown.
Process the response body.
except requests.requestexception as e:
print('Request failed:', e)
Save data: Once you've extracted the data you need from the response body, you can save it to a file, database, or other storage medium.
Set request headers: Sometimes, you may need to set some request headers, such as user-agent, to avoid being recognized as a crawler by the target and rejecting the request.
python
Copy. headers = {
user-agent': 'mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/58.0.3029.110 safari/537.3'
response = requests.get('', headers=headers)
Dealing with anti-crawler tactics: Some may use a variety of anti-crawler tactics, such as CAPTCHAs, login verification, dynamic loading, and so on. In this case, you may need to use more advanced techniques such as selenium, scrapy, etc., to bypass these strategies.
In general, processing response objects needs to be tailored to the specific situation, and may require a combination of techniques and strategies to achieve the goal.