Hi, Here is a brief guide to setup PyCharm to send its traffic generated by requests through Fiddler.

Usage:  If you get errors while  implementing an extracted  protocol from a Fiddler traces, you can forward the traffic to Fiddler, so that you can check the captured traces against the traffic generated from PyCharm to debug your code. For example, you can solve issues when receiving Code 422 in response.

Running PyCharm Traffic through Fiddler

First, you need to update proxy settings at PyCharm with Fiddler proxy details. This will ask to install Fiddler generated certificates at PyCharm. However, this step only allows PyCharm to direct it’s traffic to Fiddler, but your python code fails since this setting does not apply to urllib3 used by requests. Hence, we have to bypass certificate verification in the code.

Step 1: Add Fiddler Generated Certificates to PyCharm

• At PyCharm IDE Goto -> File -> Settings ->Appearance & Behaviour -> System Settings -> HTTP Proxy -> Provide Fiddler proxy settings as follows (Host: 127.0.0.1, Port: 8888)

• Restart PyCharm -> It will prompt to Accept the Fiddler generated certificates for JetBrains.

• You can check the saved certificates at File -> Settings ->Tools-> Server Certificates

Step2: Update Python Code

In the python code, I’m using requests package to send HTTPS requests. Update the request with an additional argument as verify=False. Otherwise, it will throw an verification failed exception (ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:646))

import requests

initResponse = requests.get(initURL, params=initParams, headers=headerInit,verify=False)

Now, it will only give a warning (InsecureRequestWarning: Unverified HTTPS request is being made to host ‘127.0.0.1’. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
InsecureRequestWarning,) and pass the code. Assuming you are aware of the security of the URL you are visiting, this can help you forward PyCharm traffic through Fiddler without much hassle.

Cheers ! 🙂