'x' not in list while iterating over list

Question

What I am attempting to do is iterate over a list of comments, remove the current comment that has been added to a value called cText, and if cText goes over 9000 characters make a recursive call into the same function and add it's returned value into botComments. I'm also attempting to merge the returned botComments list from a recursed function to the top-most botComments list with botComments + repliesToComments(comments, author) though I don't know if I'm doing anything right. Oddly, it also seems it can't find a comment in a list that for-sure has the comment throwing the exception I pasted below. I was horrible at recursion during my AP Comp-Sci class though I wish to learn what I'm doing wrong from whomever can fix my mess of code below. Thanks :)

Here's my current exception:

Traceback (most recent call last):
  File "C:\Users\Josh\Desktop\bot.py", line 62, in <module>
    print(repliesToComments(submission.comments, submission.author.name))
  File "C:\Users\Josh\Desktop\bot.py", line 36, in repliesToComments
    botComments + repliesToComments(comments, author)
  File "C:\Users\Josh\Desktop\bot.py", line 39, in repliesToComments
    comments.remove(comment)
ValueError: list.remove(x): x not in list

Here's my code:

def repliesToComments(comments, author):
    botComments = []
    multiReplies = False

    cText = "Here is a list of all the comments /u/" + author + ''' has submitted to top-level comments:
***
Original Comment | /u/''' + author + ''''s Reply
---------|---------
'''

    for comment in comments[:]:
        if (hasattr(comment, "replies")):
            for comment2 in comment.replies:
                if (hasattr(comment2, "author") and comment2.author.name == author):
                    oCommentLink = "[" + comment.body.replace("\n", "")[:50] + "](" + submission.permalink + "" + comment2.parent_id.replace("t1_", "") + ")..."
                    rCommentLink = "[" + comment2.body.replace("\n", "")[:50] + "](" + submission.permalink + "" + comment2.name.replace("t1_", "") + ")..."
                    if (len(cText) + len(oCommentLink + " | " + rCommentLink + "\n") > 9000): #Stop here to make sure we don't go over 10000 char limit!
                        multiReplies = True
                        cText += '''
***
[FAQ](http://pastebin.com/raw.php?i=wUGmE8X5) | Generated at ''' + datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S") + " PST" + " | *This comment only shows a partial amount of OPs total replies due to character limit. The rest are shown in a reply to this comment.*"
                        botComments.append(cText)
                        botComments + repliesToComments(comments, author)
                        break
                    cText += oCommentLink + " | " + rCommentLink + "\n"
        comments.remove(comment)

    if (multiReplies == False):
        cText += '''
***
[FAQ](http://pastebin.com/raw.php?i=wUGmE8X5) | Generated at ''' + datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S") + " PST"

    botComments.append(cText)
    return botComments

Answer 1

You are calling repliesToComments() recursively, but with the exact same arguments. This can only lead to problems.

Your recursive call is removing entries from the same list, and when it returns, those entries will still be gone. But because you loop over a copy of the list, your outer call won't be updated and try to remove comments the inner recursive call removed already.

Perhaps you wanted to call repliesToComments() for a different set of comments when recursing? I suspect you meant to call it for comment.replies instead?

Another problem your code has is that you ignore the return value of the recursive call:

botComments + repliesToComments(comments, author)

This adds the list botComments and the return value of the recursive call, creating a new list, which you then drop to the floor by not assigning it to a variable. You probably want to use:

botComments += repliesToComments(comments, author)

instead.