Can the comments produce errors in python?

[newbieAuggie2019]

The error happens before comments part.

Thank you!

According to my multiple tries in IDLE, before adding the comments, it doesn't seem so. This program runs fine in IDLE:

import re
 
string1 = 'Agent Cheesecake was a double agent.'
agentNamesRegex = re.compile(r'Agent (\w)\w*')
mo0 = agentNamesRegex.sub(r'\0**', string1)
print(f"This is string1 '{string1}' with r'\0**' after censorship: {mo0}\n")

and produces the following output in IDLE:

Output:
This is string1 'Agent Cheesecake was a double agent.' with r' **' after censorship:  ** was a double agent.

>>> 

It is ONLY when I add that output as comments to the program in IDLE, and then I try to run the program with the comments, when the error message of null bytes is thrown back at me. Probably I'm not very good at explaining myself. I don't need/want to modify the program as it runs fine till I add the output as comments. THE ONLY THING THAT I WOULD LIKE TO KNOW IS WHY THE COMMENTS THROW BACK AN ERROR MESSAGE WHILE SUPPOSEDLY PYTHON DOESN'T READ INSIDE THE COMMENTS PRECEDED BY ##.

Just to clarify a bit further, the original program to see differences in substitutions is:

import re

string1 = 'Agent Cheesecake was a double agent.'
agentNamesRegex = re.compile(r'Agent (\w)\w*')
mo0 = agentNamesRegex.sub(r'\0**', string1)
mo1 = agentNamesRegex.sub(r'\1**', string1)
print(f"This is string1 '{string1}' with r'\0**' after censorship: {mo0}\n")
print(f"This is string1 '{string1}' with r'\1**' after censorship: {mo1}\n")

which also runs fine in IDLE, producing the following output:

Output:
This is string1 'Agent Cheesecake was a double agent.' with r' **' after censorship:  ** was a double agent.

This is string1 'Agent Cheesecake was a double agent.' with r'  **' after censorship:  C** was a double agent.
>>> 

And it also runs fine till I add the output as comments to the program in IDLE (but before that, it runs fine). I only simplify the program to make the question of why those comments are read in IDLE and throw back an error message. I hope to have explained myself better now, sorry for not transmitting my doubt clearer before.

All the best,