Develop Reference

Importing variable from called script repeats the entire calling script

I have a main.py file
import common_functions as conf
print("Main File:")
filename = conf.testing()
from TC import TC
and I want to assign the below return statement as a variable "filename"
common_functions.py
def testing():
print("This should only print once!")
return "awesome file"
I want to then be able to access this variable, in another file that I am importing (TC )
TC.py
from main import filename
print("TC File:")
print(f"Filename is: {filename}")
however, currently, if I do this, then the output is:
Main File:
This should only print once!
Main File:
This should only print once!
TC File:
Filename is: awesome file
I am really struggling with this one, as I am trying to pass a variable into the called scripts, but that variable is only named from another function... so it seems as though everytime I it's called, then the function kicks off again
I would like to be able to set the variable filename in the main file from the function it is calling, and then in the called file (TC.py) I would like to be able to access that variable as a string, not rerun everything.
Is that possible?

Is there any way to access variable in one function of a file to another file

I have 2 files prgm.py and test.py
1.prgm.py
def move(self)
H=newtest.myfunction()
i= H.index(z)
user=newuser.my_function()
print(user[i])
How will i get user[i] in the other code named test.py

Use an import statement in the other file;
Like this - from prgm import move
Note: For this to work both of the files needs to be in the same folder or the path to the file you are importing needs to be in your PYTHONPATH

Instead of printing the result, you can simply return it. In the second file, you just import the function from this source file and call it.
Given the situation, move is actually a class method, so you need to import the whole class and instance it in the second file
prgm.py
class Example:
def move(self):
H = newtest.myfunction()
i = H.index(z)
user = newuser.my_function()
return user[i]
test.py
from prgm import Example
example = Example()
user = example.move()
# do things with user

Python3.6 |- Import a module from a list with __import__ -|

I'm creating a really basic program that simulates a terminal with Python3.6, its name is Prosser(The origin is that "Prosser" sounds like "Processer" and Prosser is a command processer).
A problem that I'm having is with command import, this is, all the commands are stored in a folder called "lib" in the root folder of Prosser and inside it can have folders and files, if a folder is in the "lib" dir it can't be named as folder anymore, its name now is package(But this doesn't care for now).
The interface of the program is just a input writed:
Prosser:/home/pedro/documents/projects/prosser/-!
and the user can type a command before the text, like a normal terminal:
Prosser:/home/pedro/documents/projects/prosser/-! console.write Hello World
let's say that inside the "lib" folder exists one folder called "console" and inside it has a file called "write.py" that has the code:
class exec:
def main(args):
print(args)
As you can see the first 2 lines is like a important structure for command execution: The class "exec" is the main class for the command execution and the def "main" is the main and first function that the terminal will read and execute also pass the arguments that the user defined, after that the command will be responsible to catch any error and do what it will be created to do.
At this moment, everything is ok, but now comes the true help that I need of U guys, the command import.
Like I writed the user can type any command, and in the example above I typed a "console.write Hello World" and exists one folder called "console" and one file "write.py". The point is that the packages can be defined by a "dot", this is:
-! write Hello World
Above I only typed "write" and this says that the file is only inside the "lib" folder, it doesn't has a package to storage and separate it, so it is a Freedom command(A command that doesn't has packages or nodes).
-! console.write Hello World
Now I typed above "console.write" and this says that the file has a package or node to storage and separate it, this means that it is a Tied command(A command that has packages or nodes).
With that, a file is separated from the package(s) with a dot, the more dots you put, more folders will be navigated to find the file and proceed to the next execution.
Code
Finnaly the code. With the import statement I tryied this:
import os
import form
curDir = os.path.dirname(os.path.abspath(__file__)) # Returns the current direrctory open
while __name__ == "__main__":
c = input('Prosser:%s-! ' % (os.getcwd())).split() # Think the user typed "task.kill"
path = c[0].split('.') # Returns a list like: ["task", "kill"]
try:
args = c[1:] # Try get the command arguments
format = form.formater(args) # Just a text formatation like create a new line with "$n"
except:
args = None # If no arguments the args will just turn the None var type
pass
if os.path.exists(curDir + "/lib/" + "/".join(path) + ".py"): # If curDir+/lib/task/kill.py exists
module = __import__("lib." + '.'.join(path)) # Returns "lib.task.kill"
module.exec.main(args) # Execute the "exec" class and the def "**main**"
else:
pathlast = path[-1] # Get the last item, in this case "kill"
path.remove(path[-1]) # Remove the last item, "kill"
print('Error: Unknow command: ' + '.'.join(path) + '. >>' + pathlast + '<<') # Returns an error message like: "Error: Unknow command: task. >>kill<<"
# Reset the input interface
The problem is that when the line "module = __import__("lib." + '.'.join(path))" is executed the console prints the error:
Traceback (most recent call last):
File "/home/pedro/documents/projects/prosser/main.py", line 18, in <module>
module.exec.main(path) # Execute the "exec" class and the def "**main**"
AttributeError: module 'lib' has no attribute 'exec'
I also tried to use:
module = \_\_import\_\_(curDir + "lib." + '.'.join(path))
But it gets the same error. I think it's lighter for now. I'd like if someone help me or find some replacement of the code. :)

I think you have error here:
You have diffirent path here:
if os.path.exists(curDir + "/lib/" + "/".join(path) + ".py")
And another here, you dont have curDir:
module = __import__("lib." + '.'.join(path)) # Returns "lib.task.kill"
You should use os.path.join to build paths like this:
module = __import__(os.path.join(curdir, 'lib', path + '.py'))

Global file initialization in flask- python

I have been googling to find how to create a global file, which will open till my application is completed . Need to write the output of all modules in a view in single file. so that users can download this file as a report once application is completed running from Front end. This is the class I have created
import time
class FileOperations:
def __init__(self):
self.current_time = time.strftime('%Y-%m-%d_%H-%M-%S')
self.outfile = open("reports/username_" + self.current_time + ".txt", 'w')
self.outfile.write("Final Report \n")
self.outfile.write("*****************")
I want this file to get it generated when the application start running & should be available for all modules

A context manager is a way to safely handle operations such as writing to file. It also allows you to better trace when file opens or closes.
I suggest you take the time when the application starts, and reuse that file as I take it you intended. That's probably "safer" than keeping the file open.
def get_time():
global start_time
start_time = time.strftime('%Y-%m-%d_%H-%M-%S')
def write_to_file():
with open('reports/username_{}.txt'.format(start_time), 'a') as f:
f.write("Final Report \n")
f.write("*****************")
if 'start_time' not in globals():
get_time()
The conditional will run each time the module is imported. By checking if its already defined in the module scope, we make sure to only define it once.

import issue using exec(compile()) in thread

Windows 10, Python 3.5.1 x64 here.
This is weird... Let's say I have this script, called do.py. Please note the import string statement:
import string
# Please note that if the print statement is OUTSIDE 'main()', it works.
# It's like if 'main()' can't see the imported symbols from 'string'
def main():
print(string.ascii_lowercase)
main()
I want to run it from a "launcher script", in a subthread, like this (launcher.py):
import sys
import threading
sys.argv.append('do.py')
def run(script, filename):
exec(compile(script, filename, 'exec'))
with open(sys.argv[1], 'rb') as _:
script = _.read()
# But this WORKS:
# exec(compile(script, sys.argv[1], 'exec'))
thread = threading.Thread(name='Runner', target=run, args=(script, sys.argv[1]))
thread.start()
thread.join()
It dies with the following error:
Exception in thread Runner:
Traceback (most recent call last):
File "C:\Program Files\Python35\lib\threading.py", line 914, in _bootstrap_inner
self.run()
File "C:\Program Files\Python35\lib\threading.py", line 862, in run
self._target(*self._args, **self._kwargs)
File "tmpgui.py", line 7, in run
exec(compile(script, filename, 'exec'))
File "do.py", line 6, in <module>
main()
File "do.py", line 4, in main
print(string.ascii_lowercase)
NameError: name 'string' is not defined
That is, the exec'ed code is not importing string properly or something like that, and within main() the string module is not visible.
This is not the full code of my project, which is too big to post here, but the bare minimum I've created which mimics the problem.
Just in case someone is curious, I'm rewriting an old program of mine which imported the main() function of a script and ran that function with the standard output streams redirected to a tkinter text box. Instead of importing a function from the script, I want to load the script and run it. I don't want to use subprocess for a whole variety of reasons, I prefer to run the "redirected" code in a thread and communicate with the main thread which is the one handling the GUI. And that part works perfectly, the only problem I have is this and I can't understand why is happening!
My best bet: I should be passing something in globals or locals dictionaries to exec, but I'm at a lost here...
Thanks a lot in advance!

exec(thing) is equivalent to exec(thing, globals(), locals()).
Thus,
the local symbol table of do.py is the local symbol table of the run function
the global symbol table of do.py is the global symbol table of launcher.py
import string imports the module and binds it to the variable in the local space, which is the local space of the run function. You can verify this:
def run(script, filename):
try:
exec(compile(script, filename, 'exec'))
finally:
assert 'string' in locals(), "won't fail because 'import' worked properly"
main has a separate local scope, but it shares the global symbol table with do.py and, consequently, with launcher.py.
Python tried to find the variable named string inside both local (it's empty) and global symbol tables of main, but failed, and raised the NameError.
Pass one empty dictionary in a call to exec:
def run(script, filename):
exec(compile(script, filename, 'exec'), {})