A technique from a chatbot

[Thomas Passin]

On 4/3/2024 1:27 AM, AVI GROSS via Python-list wrote:
> I am a tad confused by a suggestion that any kind of GOTO variant is bad. The suggestion runs counter to the reality that underneath it all, compiled programs are chock full of GOTO variants even for simple things like IF-ELSE.
> 
> Consider the code here:
> 
>>> def first_word_beginning_with_e( list_ ):
>>>       for word in list_:
>>>           if word[ 0 ]== 'e': return word
>>>       something_to_be_done_at_the_end_of_this_function()
> 
> If instead the function initialized a variable to nothing useful and in the loop if it found a word beginning with e and it still contained nothing useful, copied it into the variable and then allowed the code to complete the loop and finally returned the variable, that would simply be a much less efficient solution to the problem and gain NOTHING. There are many variants you can come up with and when the conditions are complex and many points of immediate return, fine, then it may be dangerous. But a single return is fine.
> 
> The function does have a flaw as it is not clear what it should do if nothing is found. Calling a silly long name does not necessarily return anything.
> 
> Others, like Thomas, have shown other variants including some longer and more complex ways.
> 
> A fairly simple one-liner version, not necessarily efficient, would be to just use a list comprehension that makes a new list of just the ones matching the pattern of starting with an 'e' and then returns the first entry or None. This shows the code and test it:
> 
> text = ["eastern", "Western", "easter"]
> 
> NorEaster = ["North", "West", "orient"]
> 
> def first_word_beginning_with_e( list_ ):
>    return(result[0] if (result := [word for word in list_ if word[0].lower() == 'e']) else None)
> 
> print(first_word_beginning_with_e( text ))
> print(first_word_beginning_with_e( NorEaster ))
> 
> Result of running it on a version of python ay least 3.8 so it supports the walrus operator:
> 
> eastern
> None

The OP seems to want to return None if a match is not found.  If a 
Python function ends without a return statement, it automatically 
returns None.  So nothing special needs to be done.  True, that is 
probably a special case, but it suggests that the problem posed to the 
chatbot was not posed well.  A truly useful chatbot could have discussed 
many of the points we've been discussing.  That would have made for a 
good learning experience.  Instead the chatbot produced poorly 
constructed code that caused a bad learning experience.


> [snip...]