Develop Reference

Python-How to execute code and store into variable?

So I have been struggling with this issue for what seems like forever now (I'm pretty new to Python). I am using Python 3.7 (need it to be 3.7 due to variations in the versions of packages I am using for the project) to develop an AI chatbot system that can converse with you based on your text input. The program reads the contents of a series of .yml files when it starts. In one of the .yml files I am developing a syntax for when the first 5 characters match a ^###^ pattern, it will instead execute the code and return the result of that execution rather than just output text back to the user. For example:
Normal Conversation:
- - What is AI?
- Artificial Intelligence is the branch of engineering and science devoted to constructing machines that think.
Service/Code-based conversation:
- - Say hello to me
- ^###^print("HELLO")
The idea is that when you ask it to say hello to you, the ^##^print("HELLO") string will be retrieved from the .yml file, the first 5 characters of the response will be removed, the response will be sent to a separate function in the python code where it will run the code and store the result into a variable which will be returned from the function into a variable that will give the nice, clean result of HELLO to the user. I realize that this may be a bit hard to follow, but I will straighten up my code and condense everything once I have this whole error resolved. As a side note: Oracle is just what I am calling the project. I'm not trying to weave Java into this whole mess.
THE PROBLEM is that it does not store the result of the code being run/executed/evaluated into the variable like it should.
My code:
def executecode(input):
print("The code to be executed is: ",input)
#note: the input may occasionally have single quotes and/or double quotes in the input string
result = eval("{}".format(input))
print ("The result of the code eval: ", result)
test = eval("2+2")
test
print(test)
return result
#app.route("/get")
def get_bot_response():
userText = request.args.get('msg')
print("Oracle INTERPRETED input: ", userText)
ChatbotResponse = str(english_bot.get_response(userText))
print("CHATBOT RESPONSE VARIABLE: ", ChatbotResponse)
#The interpreted string was a request due to the ^###^ pattern in front of the response in the custom .yml file
if ChatbotResponse[:5] == '^###^':
print("---SERVICE REQUEST---")
print(executecode(ChatbotResponse[5:]))
interpreter_response = executecode(ChatbotResponse[5:])
print("Oracle RESPONDED with: ", interpreter_response)
else:
print("Oracle RESPONDED with: ", ChatbotResponse)
return ChatbotResponse
When I run this code, this is the output:
Oracle INTERPRETED input: How much RAM do you have?
CHATBOT RESPONSE VARIABLE: ^###^print("HELLO")
---SERVICE REQUEST---
The code to be executed is: print("HELLO")
HELLO
The result of the code eval: None
4
None
The code to be executed is: print("HELLO")
HELLO
The result of the code eval: None
4
Oracle RESPONDED with: None
Output on the website interface
Essentially, need it to say HELLO for the "The result of the code eval:" output. This should get it to where the chatbot responds with HELLO in the web interface, which is the end goal here. It seems as if it IS executing the code due to the HELLO's after the "The code to be executed is:" output text. It's just not storing it into a variable like I need it to.
I have tried eval, exec, ast.literal_eval(), converting the input to string with str(), changing up the single and double quotes, putting \ before pairs of quotes, and a few other things. Whenever I get it to where the program interprets "print("HELLO")" when it executes the code, it complains about the syntax. Also, from several days of looking online I have figured out that exec and eval aren't generally favored due to a bunch of issues, however I genuinely do not care about that at the moment because I am trying to make something that works before I make something that is good and works. I have a feeling the problem is something small and stupid like it always is, but I have no idea what it could be. :(
I used these 2 resources as the foundation for the whole chatbot project:
Text Guide
Youtube Guide
Also, I am sorry for the rather lengthy and descriptive question. It's rare that I have to ask a question of my own on stackoverflow because if I have a question, it usually already has a good answer. It feels like I've tried everything at this point. If you have a better suggestion of how to do this whole system or you think I should try approaching this another way, I'm open to ideas.
Thank you for any/all help. It is very much appreciated! :)

The issue is that python's print() doesn't have a return value, meaning it will always return None. eval simply evaluates some expression, and returns back the return value from that expression. Since print() returns None, an eval of some print statement will also return None.
>>> from_print = print('Hello')
Hello
>>> from_eval = eval("print('Hello')")
Hello
>>> from_print is from_eval is None
True
What you need is a io stream manager! Here is a possible solution that captures any io output and returns that if the expression evaluates to None.
from contextlib import redirect_stout, redirect_stderr
from io import StringIO
# NOTE: I use the arg name `code` since `input` is a python builtin
def executecodehelper(code):
# Capture all potential output from the code
stdout_io = StringIO()
stderr_io = StringIO()
with redirect_stdout(stdout_io), redirect_stderr(stderr_io):
# If `code` is already a string, this should work just fine without the need for formatting.
result = eval(code)
return result, stdout_io.getvalue(), stderr_io.getvalue()
def executecode(code):
result, std_out, std_err = executecodehelper(code)
if result is None:
# This code didn't return anything. Maybe it printed something?
if std_out:
return std_out.rstrip() # Deal with trailing whitespace
elif std_err:
return std_err.rstrip()
else:
# Nothing was printed AND the return value is None!
return None
else:
return result
As a final note, this approach is heavily linked to eval since eval can only evaluate a single statement. If you want to extend your bot to multiple line statements, you will need to use exec, which changes the logic. Here's a great resource detailing the differences between eval and exec: What's the difference between eval, exec, and compile?

It is easy just convert try to create a new list and add the the updated values of that variable to it, for example:
if you've a variable name myVar store the values or even the questions no matter.
1- First declare a new list in your code as below:
myList = []
2- If you've need to answer or display the value through myVar then you can do like below:
myList.append(myVar)
and this if you have like a generator for the values instead if you need the opposite which means the values are already stored then you will just update the second step to be like the following:
myList[0]='The first answer of the first question'
myList[1]='The second answer of the second question'
ans here all the values will be stored in your list and you can also do this in other way, for example using loops is will be much better if you have multiple values or answers.

Why is find_withtag wont work in python

This is part of my code, the id of image wont print even I use the withtag function. I think the function canvas.delete won't work is also the same problem, it seem the tag is inserted as "123","456". However, the tag I expected to use and get is 123 instead of '123'. And I guess it's the main problem I can't get the id I want with the findtag function.
CurrentImage=Note[NoteIndexLocal]
Temp=canvas.create_image(XShow,YShow,image=CurrentImage,tag=123)
print canvas.find_withtag(123) #This Wont Work,printed()
canvas.delete(123) #This Wont Work
print canvas.gettags(Temp) #printed '123'

From: http://effbot.org/tkinterbook/canvas.htm
Tags are symbolic names attached to items. Tags are ordinary strings,
and they can contain anything except whitespace (as long as they don’t
look like item handles).
Use str(123) instead of 123
EDIT: correct answer is in text from doc "as long as they don’t look like item handles". Number 123 looks like item handle (print Temp to see how it looks like) so it doesn't work. Use text like "a123" and it will work.

using list instead of number or string in the query

I would like to use a list of int to be used in a query as below:
db.define_table('customer',Field('name'),Field('cusnumber','integer'))
def custmr():
listOfNumbers=[22,12,76,98]
qry=db(db.customer.cusnumber==listOfNumbers).select(db.customer.name)
print qry
this arise an issue that the only accepted data type in the query is int or str.
Is there any way to avoid this issue (preferably by not using for loop)
Regards

It is really difficult to know what you're trying to ask, but from the syntax of db.define_table(...), I take a wild guess you're on web2py and trying to do a query which fetch any int in your listOfNumbers.
You may use contains attribute like this:
# if all=True, cusnumber will need to contains all listOfNumbers, False means any
qry=db(db.customer.cusnumber.contains(listOfNumbers, all=False)).select(db.customer.name)
You can read more in details in HERE
As OP replied that contains only works for string, I'm going to suggest using for/loop will be a better answer:
listOfNumbers=[22,12,76,98]
for each in listOfNumbers:
qry=db(db.customer.cusnumber==each).select(db.customer.name)
# ... do your stuff or whatever ...

Assuming you want the set of records for which the cusnumber is in listOfNumbers, you should use the .belongs method:
qry = db(db.customer.cusnumber.belongs(listOfNumbers)).select(db.customer.name)

Checking for specific output from Python's DNS Resolver Query

I'm trying to write something that will ask users to input a specific domain (say, Google.com), and if _spf.google.com is in the SPF TXT record for Google.com, I want it to say "Yup". If not, I want it to say "Nope." Right now, the code will ask me for the domain, and it'll look up the SPF record, but I can't get it to say "yup." Why not? I've tried turning it into a string, but even that wouldn't get me what I wanted. What am I doing wrong here?
To add to that, what would you guys recommend is a good jumping off point for figuring out what code I'd need to write to figure out how many DNS lookups an SPF record is ultimately using?
import dns.resolver
question= raw_input("What domain do you want? ")
def PrintandGoogle(question):
answer=dns.resolver.query(question,"TXT")
for data in answer:
print data
if "_spf.google.com" in answer:
print "Yup."
else:
print "Nope."
printAndGoogle(question)

If your if is inside your loop:
if "_spf.google.com" in data.to_text():
If your if is outside your loop:
if any("_spf.google.com" in data.to_text() for data in answer):

Python: Matching & Stripping port number from socket data

I have data coming in to a python server via a socket. Within this data is the string '<port>80</port>' or which ever port is being used.
I wish to extract the port number into a variable. The data coming in is not XML, I just used the tag approach to identifying data for future XML use if needed. I do not wish to use an XML python library, but simply use something like regexp and strings.
What would you recommend is the best way to match and strip this data?
I am currently using this code with no luck:
p = re.compile('<port>\w</port>')
m = p.search(data)
print m
Thank you :)

Regex can't parse XML and shouldn't be used to parse fake XML. You should do one of
Use a serialization method that is nicer to work with to start with, such as JSON or an ini file with the ConfigParser module.
Really use XML and not something that just sort of looks like XML and really parse it with something like lxml.etree.
Just store the number in a file if this is the entirety of your configuration. This solution isn't really easier than just using JSON or something, but it's better than the current one.
Implementing a bad solution now for future needs that you have no way of defining or accurately predicting is always a bad approach. You will be kept busy enough trying to write and maintain software now that there is no good reason to try to satisfy unknown future needs. I have never seen a case where "I'll put this in for later" has led to less headache later on, especially when I put it in by doing something completely wrong. YAGNI!
As to what's wrong with your snippet other than using an entirely wrong approach, angled brackets have a meaning in regex.

Though Mike Graham is correct, using regex for xml is not 'recommended', the following will work:
(I have defined searchType as 'd' for numerals)
searchStr = 'port'
if searchType == 'd':
retPattern = '(<%s>)(\d+)(</%s>)'
else:
retPattern = '(<%s>)(.+?)(</%s>)'
searchPattern = re.compile(retPattern % (searchStr, searchStr))
found = searchPattern.search(searchStr)
retVal = found.group(2)
(note the complete lack of error checking, that is left as an exercise for the user)