This comprehensive guide will walk you through how to fix the
requests.exceptions.InvalidSchema: No Connection Adapters Found error in Python's
requests library. This error occurs when the library encounters a URL with an unsupported schema. We will cover the common causes of this error, and provide step-by-step solutions to resolve it.
Table of Contents
- Understanding the Error
- Identifying the Cause
- Step-by-Step Solutions
- Solution 1: Check the URL
- Solution 2: Install the Required Adapter
- Solution 3: Register the Connection Adapter
Understanding the Error
requests.exceptions.InvalidSchema: No Connection Adapters Found is an error that occurs when the
requests library cannot establish a connection to the specified URL. This is usually because the URL has an unsupported schema, such as
Here's an example of the error message you might encounter:
requests.exceptions.InvalidSchema: No connection adapters were found for 'file:///path/to/local/file.txt'
Identifying the Cause
The most common causes of this error are:
- The URL provided is incorrect, misspelled, or missing a schema (e.g.,
requestslibrary does not support the URL's schema.
- A custom connection adapter is not properly registered with the
Solution 1: Check the URL
Ensure that the URL provided is correct and contains the correct schema. The
requests library only supports
https:// out of the box.
Instead of using an incorrect URL like this:
import requests url = "file:///path/to/local/file.txt" response = requests.get(url)
Use a correct URL with a supported schema:
import requests url = "https://example.com/path/to/resource" response = requests.get(url)
Solution 2: Install the Required Adapter
If your URL has a schema that is not natively supported by the
requests library, you may need to install an additional connection adapter. For example, to use the
requests library with an
ftp:// URL, you can install the
requests-ftp adapter using pip:
pip install requests-ftp
Then, use the adapter in your code:
import requests from requests_ftp import FTPAdapter url = "ftp://example.com/path/to/resource" session = requests.Session() session.mount("ftp://", FTPAdapter()) response = session.get(url)
Solution 3: Register the Connection Adapter
If you have created a custom connection adapter, make sure it is properly registered with the
Register a custom connection adapter:
import requests from my_custom_adapter import MyCustomAdapter url = "custom://example.com/path/to/resource" session = requests.Session() session.mount("custom://", MyCustomAdapter()) response = session.get(url)
1. What is a connection adapter?
Connection adapters are responsible for handling the implementation details of making a request to a specific URL schema. They provide an interface between the
requests library and the underlying protocol, such as HTTP or FTP.
2. How do I create a custom connection adapter?
You can create a custom connection adapter by subclassing the
requests.adapters.BaseAdapter class and implementing the necessary methods, such as
3. Can I use multiple connection adapters with the
Yes, you can register multiple connection adapters with the
requests library by creating a
Session object and mounting each adapter with the
4. Why does the
requests library not support other schemas out of the box?
requests library is primarily designed for making HTTP requests, which is why it only supports
https:// by default. However, the library's architecture allows for the use of additional connection adapters to support other schemas.
5. Can I use the
requests library to fetch local files?
requests library does not natively support fetching local files using the
file:// schema. You can use Python's built-in
open() function to read local files instead.