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Restrict the Python file to read and write

I'm trying to restrict write and read access to a Python file. Suppose I have the following code:
with open('test.py', 'w+') as file:
file.write('''
open("document.txt", "w+").write("Hello, World!")
open("document.txt", "r+").read()
''')
By executing this code, a new file is created that in the new file there are two lines of code to write and read a another file.
I want the file created by executing this code (test.py) to hit PermissionError while running and not be able to create a new file or read it; Also, this file is only executable and normal commands work in it, but it can not access other files.

If I read you correctly, this is not a python problem, but an environment problem. I understand the question as something like 'how do I prevent python code from executing arbitrary reads or writes?'. There would be a trivial solution (modifying the generated test.py so it throws an error) but presumably that's not what you want.
The easiest way to make python hit a PermissionError... is to make sure it doesn't have permissions. So run your code as a user with extremely limited permissions---specifically no write permissions anywhere---or perhaps no default permissions at all, and use something like facls to grant permission to read specific files explicitly from a more priveleged sentinel process. (This assumes you are running Linux, but there are likely other ways to do this in different OSs).
Alternatively, look into various sandboxing techniques to give you a python interpreter with the relavent modules replaced with modules which throw errors, or an environment where outside modification is impossible.
It would help if you made it clearer why this is important, and why you are writing a python script with another python script (is this just an example of malicious action?).

You could technically change the permission of the file itself on the filesystem your trying to access.
Check the previous thread about changing permissions
os.chmod(path, <permission value>)
Where 000 is to disable anyone other than root to edit on linux.

Running python file with arguments works in terminal, but I need to use it in a different script

Running the following works perfectly when I do it in my terminal
python3 number_detection.py --train_predict 'P' --file 'Images/2/_newsize_1.png'
However, I need to be able to perform this task in a different script. I'm looping through images and want to return what they're recognized as.
So running the above in the terminal works fine, but how do I translate that code to work in a different .py file?

Maybe there is a way to advise you without seeing your number_detection.py file, but it would definitely allow me to give you more concrete advice if you post that.
Right now I would say, most likely you can put everything in your number_detection.py file, and turn it into a number_detection.py function that takes in your arguments
def number_detection(train_predict, file):
#put your original code here
Then in your image processing file,
from number_detection import number_detection
and now you can use that other function in your new file

Python command to execute non-Python (MQL5) files?

I have a collection of expert advisor (EA) scripts written in the MQL5 programming language for the stock/forex trading platform, MetaTrader5. The extension of these files is mq5. I am looking for a way to programatically run these MQL5 files from my Python script on a regular basis. The EAs do some price transformations, eventually saving a set of csv files that will later be read by my Python script to apply Machine Learning models on them.
My first natural choice was the Python API for MetaTrader5. However, according to its documentation, it "is designed for convenient and fast obtaining of exchange data via interprocessor communication directly from the MetaTrader 5 terminal" and as such, it doesn't provide the functionality I need to be able to run MQL scripts using Python.
I have found some posts here on SO (such as #1, #2) about executing non-python files using Python but those posts seemed to always come with the precondition that they already had Python code written in them, only the extension differed - this is different from my goal.
I then came across Python's subprocess module and started experimenting with that.
print(os.path.isfile(os.path.join("path/to/dir","RSIcalc.mq5")))
with open(os.path.join("path/to/dir","RSIcalc.mq5")) as f:
subprocess.run([r"C:\Program Files\MetaTrader 5\terminal64.exe", f], capture_output=True)
The print statement returns True, so the mq5 file exists in the specified location. Then the code opens the MetaTrader5 terminal but nothing else happens, the EA doesn't get executed, process finishes immediately after that.
Am I even on the right track for what I'm trying to achieve here? If yes, what might be the solution for me to run these MQL5 scripts programatically from Python?
Edit:
I use Windows 10 64-bit.

subprocess is indeed the right module for what you want to achieve. But let's look at what you're doing here:
with open(os.path.join("path/to/dir","RSIcalc.mq5")) as f
You're creating a file descriptor handle called f, which is used to write or read contents from a file. If you do print(f) you'll see that it's a python object, that converted to string looks like <_io.TextIOWrapper name='RSIcalc.mq5' mode='r' encoding='UTF-8'>. It is extremely unlikely that such a string is what you want to pass as a command-line parameter to your terminal executable, which is what happens when you include it in your call to subprocess.run().
What you likely want to do is this:
full_path = os.path.abspath(os.path.join("path/to/dir","RSIcalc.mq5"))
result = subprocess.run([r"C:\Program Files\MetaTrader 5\terminal64.exe", full_path], capture_output=True)
Now, this assumes your terminal64 can execute arbitrary scripts passed as parameters. This may or may not be true - you might need extra parameters like "-f" before passing the file path, or you might have to feed script contents through the stdin pipe (unlikely, on Windows, but who knows). That's for you to figure out, but my code above should probably be your starting point.

I don’t think you need to be passing a file object to your sub process statement. In my experience. A program will run a file when the path to the file is provided as a command line argument. Try this:
subprocess.run([r"C:\\Program Files\\MetaTrader 5\\terminal64.exe", os.path.join(“path/to/dir”, “RSIcalc.mq5”], capture_output=True)
This is the same as typing C:\Program Files\MetaTrader 5\terminal64.exe path\to\dir\RSIcalc.mq5 in your terminal.

Python changing command line argument with a script

I'm new to coding so this "obvious" action isn't really obvious to me. I've read on W3schools.com and other forums on the web about my problem but can't figure if I'm looking at the wrong solution or just can't do it.
I was able to run this python script from that site https://www.pyimagesearch.com/2018/11/12/yolo-object-detection-with-opencv/
It basically opens a command-line terminal which in you do insert argument and the script performs an object detection action.
What I want to do, is creating a script that automatically gets the image input path and then pastes it in the command line.
import os
imageFile = test1
os.system("python yolo.py --image {}.jpg --yolo yolo-coco").format(imageFile)
Furthermore, I'm asking myself how to get rid of the command line argument to paste arguments. Is there any way to accomplish this by directly putting the image's path in the base script?
Thanks in advance for the help.

Python interactive library(pymidas) session warning

I'm using Python2.7 and a library called pymidas.
Within my python script I call the library with the following comand:
from pymidas import midas
midas.do('INDISK/FITS test.fits test.bdf')
All the code that I have further written does exactly what I want, but whenever the script imports midas I first get a welcome output of (py)midas, which is ok with me, but afterwards it asks me if I want a parallel or a new session.
Saddly this point needs human interaction in selecting parallel mode. By reading the documentation of midas I found, that midas has an option (-P) which causes exactly what I need, and forces midas to open without any questions asked and directly going to parallel mode.
Does anybody know how to achieve this in my python script?
Thanks!

At the end of your script add :
midas.do('.exit')
This ensures you dont get asked the next time you run the script.