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running 2 python scripts without them effecting each other

I have 2 python scripts I'm trying to run side by side. However, each of them have to open and close and reopen independently from each other. Also, one of the scripts is running inside a shell script.
Flaskserver.py & ./pyinit.sh
Flaskserver.py is just a flask server that needs to be restarted everynow and again to load a new page. (cant define all pages as the html is interchangeable). the pyinit is runs as xinit ./pyinit.sh (its selenium-webdriver pythoncode)
So when the Flaskserver changes and restarts the ./pyinit needs to wait about 20 seconds then restart as well.
Either one of these can create errors so I need to be able to check if Flaskserver has an error before restarting ./pyinit if ./pyinit errors i need to set the Flaskserver to a default value and then relaunch both of them.
I know a little about subprocess but I'm unsure on how it can deal with errors and stop-start code.

Rather than using sub-process I would recommend you to create a different thread for your processes using multithread.
Multithreading will not solve the problem if global variables are colliding, but by running them in different scripts, while you might solve this, you might collide in something else like a log file.
Now, if you keep both processes running from a single process that takes care of keeping them separated and assigning different global variables where necessary, you should be able to keep a better control. Using things like join and lock from the multithreading library, will also ensure that they don't collide and it should be easy to put a process to sleep while the other is running (as per waiting 20 secs).
You can keep a thread list as a global variable, as well as your lock. I have done this successfully with CherryPy's server for example. Any more details about multithreading look into the question I linked above, it's very well explained.

Is there a way to determine if multiple users are running a particular Python script?

I have script which can be run by any user who is connected to a server. This script writes to a single log file, but there is no restriction on who can use it at one time. So multiple people could attempt to write to the log and data might be lost. Is there a way for one instance of the code to know if other instances of that code are running? Moreover, is it possible to gather this information dynamically? (ie not allow data saving for the second user until the first user has completed hes/her task)
I know I could do this with a text file. So I could write the user name to the file when the start, then delete it when they finish, but this could lead to errors if the either step misses, such as an unexpected script termination. So what other reliable ways are there?
Some information on the system: Python 2.7 is installed on a Windows 7 64-bit server via Anaconda. All connected machines are also Windows 7 64-bit. Thanks in advance

Here is an implementation:
http://www.evanfosmark.com/2009/01/cross-platform-file-locking-support-in-python/
If you are using a lock, be aware that stale locks (that are left by hung or crashed processes) can be a bitch. Have a process that periodically searches for locks that were created longer than X minutes ago and free them.
It just in't clean allowing multiple users to write to a single log and hoping things go ok..
why dont you write a daemon that handles logs? other processes connect to a "logging port" and in the simplest case they only succeed if no one else has connected.
you can just modify the echoserver example given here: (keep a timeout in the server for all connections)
http://docs.python.org/release/2.5.2/lib/socket-example.html
If you want know exactly who logged what, and make sure no one unauthorized gets in, you can use unix sockest to restrict it to only certain uids/gids etc.
here is a very good example

NTEventLogHandler is probably the easiest way for logging to a given Windows machine/server, but it might make more sense to use SyslogHandler if you have a syslog sink on a Unix server.
The catch I can think of with SyslogHandler is that you'll likely need to poke holes through the Windows firewall in order to send packets over the syslog protocol, i.e., 514/TCP ("reliable syslog") and 514/UDP (traditional or "unreliable syslog").

Automate Python Script

I'm running a python script manually that fetches data in JSON format.How do I automate this script to run automatically on an hourly basis?
I'm working on Windows7.Can I use tools like Task scheduler?If I can use it,what do I need to put in the batch file?

Can I use tools like Task scheduler?
Yes. Any tool that can run arbitrary programs can run your Python script. Pick the one you like best.
If I can use it,what do I need to put in the batch file?
What batch file? Task Scheduler takes anything that can be run, with arguments—a C program, a .NET program, even a document with a default app associated with it. So, there's no reason you need a batch file. Use C:\Python33\python.exe (or whatever the appropriate path is) as your executable, and your script's path (and its arguments, if any) as the arguments. Just as you do when running the script from the command line.
See Using the Task Scheduler in MSDN for some simple examples, and Task Scheduler Schema Elements or Task Scheduler Scripting Objects for reference (depending on whether you want to create the schedule in XML, or via the scripting interface).
You want to create an ExecAction with Path set to "C:\Python33\python.exe" and Arguments set to "C:\MyStuff\myscript.py", and a RepetitionPattern with Interval set to "PT1H". You should be able to figure out the rest from there.
As sr2222 points out in the comments, often you end up scheduling tasks frequently, and needing to programmatically control their scheduling. If you need this, you can control Task Scheduler's scripting interface from Python, or build something on top of Task Scheduler, or use a different tool that's a bit easier to get at from Python and has more helpful examples online, etc.—but when you get to that point, take a step back and look at whether you're over-using OS task scheduling. (If you start adding delays or tweaking times to make sure the daily foo1.py job never runs until 5 minutes after the most recent hourly foo0.py has finished its job, you're over-using OS task scheduling—but it's not always that obvious.)

May I suggest WinAutomation or AutoMate. These two do the exact same thing, except the UI is a little different. I prefer WinAutomation, because the scripts are a little easier to build.

Yes, you can use the Task Scheduler to run the script on an hourly bases.
To execute a python script via a Batch File, use the following code:
start path_to_python_exe path_to_python_file
Example:
start C:\Users\harshgoyal\AppData\Local\Continuum\Anaconda3\python.exe %UserProfile%\Documents\test_script.py
If python is set as Window’s Environment Window then you can reduce the syntax to:
start python %UserProfile%\Documents\test_script.py
What I generally do is run the batch file once via Task Scheduler and within the python script I call a thread/timer every hour.
class threading.Timer(interval, function, args=None, kwargs=None)

Python: Running Daemon Processes in Windows7

I had a program that Scraped certain data from certain Web-Pages, and when the Web-Pages changed, acted accordingly.
How would one set up the program so it continues to run in the background?
I don't need any specifics
I'm just really confused on this concept and would appreciate whatever help anybody has to offer.

start path-to-pythonw.exe your-code.py
pythonw means without console.
start means start on background.
if your python is installed system-wide, you can probably start your-code.pyw
.pyw is associated with pythonw.exe
remember you cannot use print (to stdout) in this case.

If you want to be able to just start your process and have it background itself and do a few more typical things that "daemon" processes do in Unix, look here: How do you create a daemon in Python?

There is no concept of "background" in Windows. But the UNIX shell concept of a background process can be reasonably emulated by running your Python script as a Windows service. There are a couple of suggestions in this question: Is it possible to run a Python script as a service in Windows? If possible, how?
For casual use, I suggest that you learn how to use srvany from the second answer.

You simply need to leave your program running! Please google "python daemon" and see how to implement a persistent background process in Python.
Now, you cannot know when a website changes unless you poll it. If the website is well designed, the page you are trying to poll will have a "Last-Modified" header, you can make a "HEAD" request every so often (be nice: don't poll like crazy) and act when Last-Modified is >= than the one on record. If the site is not well designed, it will not have a reliable Last-Modified or ETAG header, in that case you will have to parse manually and check for changes yourself.
Cheers.

How can I detect what other copy of Python script is already running

I have a script. It uses GTK. And I need to know if another copy of scrip starts. If it starts window will extend.
Please, tell me the way I can detect it.

You could use a D-Bus service. Your script would start a new service if none is found running in the current session, and otherwise send a D-Bus message to the running instace (that can send "anything", including strings, lists, dicts).
The GTK-based library libunique (missing Python bindings?) uses this approach in its implementation of "unique" applications.

You can use a PID file to determine if the application is already running (just search for "python daemon" on Google to find some working implementations).
If you detected that the program is already running, you can communicate with the running instance using named pipes.

The new copy could search for running copies, fire a SIGUSER signal and trigger a callback in your running process that then handles all the magic.
See the signal library for details and the list of things that can go wrong.

I've done that using several ways depending upon the scenario
In one case my script had to listen on a TCP port. So I'd just see if the port was available it'd mean it is a new copy. This was sufficient for me but in certain cases, if the port is already in use, it might be because some other kind of application is listening on that port. You can use OS calls to find out who is listening on the port or try sending data and checking the response.
In another case I used PID file. Just decide a location and a filename, and everytime your script starts, read that file to get a PID. If that PID is running, it means another copy is already there. Otherwise create that file and write your process ID in it. This is pretty simple. If you are using django then you can simply use django's daemonizer: "from django.utils import daemonize". Otherwise you can use this script: http://www.jejik.com/articles/2007/02/a_simple_unix_linux_daemon_in_python/