Fatal Python error: Cannot recover from stack overflow

First Check

• I added a very descriptive title to this issue.
• I used the GitHub search to find a similar issue and didn’t find it.
• I searched the FastAPI documentation, with the integrated search.
• I already searched in Google “How to X in FastAPI” and didn’t find any information.
• I already read and followed all the tutorial in the docs and didn’t find an answer.
• I already checked if it is not related to FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

def loop():
    s = "ss"
    while s == "ss":
        error = False
        try:
            driver.find_element_by_xpath("/html/body/div[4]/div[1]/div[3]/div/div[2]/div/button").click()
        except:
            print(f'''{Fore.RED}[-] The captcha is unsolved!{Fore.RESET}''')
            sleep(8)
            driver.refresh()
            error = True
        if not error:
            s = "notss"
    try:
        sleep(2)
        driver.find_element_by_xpath('//*[@id="sid2"]/div/form/div/input').send_keys(vidUrl)
        
        sleep(1)
        driver.find_element_by_xpath('//*[@id="sid2"]/div/form/div/div/button').click()
        
        sleep(5)
        driver.find_element_by_xpath('//*[@id="c2VuZE9nb2xsb3dlcnNfdGlrdG9r"]/div[1]/div/form/button').click()
        
        sleep(6)
        hearts = driver.find_element_by_xpath('//*[@id="c2VuZE9nb2xsb3dlcnNfdGlrdG9r"]/span').text.split()
        
        int(hearts[0])
        print(f'''{Fore.GREEN}[+] Hearts sent!{Fore.RESET}''')
        
        sleep(5)
        driver.refresh()
        sleep(10)  
        loop()
    except:
        print(f'''{Fore.RED}[-] An error occured, Retrying..{Fore.RESET}''')
        driver.refresh()
        sleep(5)
        loop()

Description

I believe its because i have used loop a but i am unsure how to stop it from causing this error

Operating System

Windows

Operating System Details

21H2

FastAPI Version

0.71.0

Python Version

3.9.0

Additional Context

No response

[ypsah]

For the record, when raising an issue, people tend to appreciate a minimal reproducible example.

I understand you may be new to programming, so let me give you an example of how I would have gone around to troubleshooting this issue (which is by no mean the one true way, merely an example):

Step 1: put the relevant code in a separate .py file and run it

This would have highlighted that your example is missing some context about:

• driver;
• vidUrl;
• Fore;
• sleep.

From the way you use it, I understand that driver could be an instance of selenium’s WebDriver, Fore comes from colorama, sleep is time.sleep from python’s standard library, and vidUrl is probably a string containing a URL.

from time import sleep

from colorama import Fore
fom selenium.webdriver.remote.webdriver import WebDriver

driver = WebDriver()
vidUrl = "example.com"

def loop():
    s = "ss"
    while s == "ss":
        error = False
        try:
            driver.find_element_by_xpath("/html/body/div[4]/div[1]/div[3]/div/div[2]/div/button").click()
        except:
            print(f'''{Fore.RED}[-] The captcha is unsolved!{Fore.RESET}''')
            sleep(8)
            driver.refresh()
            error = True
        if not error:
            s = "notss"
    try:
        sleep(2)
        driver.find_element_by_xpath('//*[@id="sid2"]/div/form/div/input').send_keys(vidUrl)

        sleep(1)
        driver.find_element_by_xpath('//*[@id="sid2"]/div/form/div/div/button').click()

        sleep(5)
        driver.find_element_by_xpath('//*[@id="c2VuZE9nb2xsb3dlcnNfdGlrdG9r"]/div[1]/div/form/button').click()

        sleep(6)
        hearts = driver.find_element_by_xpath('//*[@id="c2VuZE9nb2xsb3dlcnNfdGlrdG9r"]/span').text.split()

        int(hearts[0])
        print(f'''{Fore.GREEN}[+] Hearts sent!{Fore.RESET}''')

        sleep(5)
        driver.refresh()
        sleep(10)
        loop()
    except:
        print(f'''{Fore.RED}[-] An error occured, Retrying..{Fore.RESET}''')
        driver.refresh()
        sleep(5)
        loop()

if __name__ == "__main__":
    loop()

Make sure that the snippet runs by itself and that it exhibits the issue you are investigating. On linux, it would mean running:

$ python reproducer.py

Where reproducer.py is the name of the file I put the code in.

If you are using an IDE, refer to its documentation on how to run standalone python scripts.

Note: the snippet I posted above does not work as-is. I suspect this is because one needs to setup a server for selenium. If that were important for the issue at hand, you would need to explain how to set that up so others can run your code and reproduce the issue. Fortunately, it’s not relevant, so let’s forget about it.

Note#2: By now, it should already be clear that the issue is not related to fastapi as fastapi does not appear anywhere in our snippet and the issue still occurs. That makes stackoverflow.com a better place to ask a question.

Step 2: remove as much code as you can

It is best to go step by step about it:

• remove a few lines;
• run the code;
• make sure it still fails in the same way.

In order, I think I would have removed:

• the calls to sleep: to make the code faster to run;
• lines that contain driver: to eliminate the dependency on selenium;
• lines that contain Fore: to eliminate the dependency on colorama.

That would have gotten me something like:

def loop():
    s = "ss"
    while s == "ss":
        error = False
        try:
            pass
        except:
            error = True
        if not error:
            s = "notss"
    try:
        loop()
    except:
        loop()

if __name__ == "__main__":
    loop()

Then, if it hadn’t been clear by now what the issue is, I would have removed either the while look of the try/except block.

Only the version with the try/except block would have kept showing the issue, so that is the one I would have kept. We are now down to:

$ cat reproducer.py
def loop():
    try:
        loop()
    except:
        loop()

if __name__ == "__main__":
    loop()

Which, thinking about it, is equivalent to:

def loop():
    loop()

if __name__ == "__main__":
    loop()

Somewhere along the way, you might have noticed that the error message changed and is now:

$ python reproducer.py
Traceback (most recent call last):
  File "/tmp/tmp.KhplXQz0Am/reproducer.py", line 5, in <module>
    loop()
  File "/tmp/tmp.KhplXQz0Am/reproducer.py", line 2, in loop
    loop()
  File "/tmp/tmp.KhplXQz0Am/reproducer.py", line 2, in loop
    loop()
  File "/tmp/tmp.KhplXQz0Am/reproducer.py", line 2, in loop
    loop()
  [Previous line repeated 996 more times]
RecursionError: maximum recursion depth exceeded

It could mean that I removed too many lines and am now getting into a totally unrelated issue, but actually, if you read about it, you will find that the two errors are related and this new error message gives you more information about the issue’s root cause than the old one.

Step 3: Search online for the error message

Use your favorite search engine to research: “RecursionError: maximum recursion depth exceeded”.

If you don’t find any explanation about it that fits your use case or you don’t understand the answers, only then consider asking a question on stackoverflow.com (or the relevant github project, although in this case stackoverflow.com is the way I would go myself).

Read about how to ask a good question if you can, it’ll help you get the best answer.

[tiangolo]

It seems from your code that you are not using FastAPI, in that case this wouldn’t be the place to ask.

Funnily enough, the right place would be on StackOverflow (the same name as your error 😅)