Press enter stops computing python - python-3.x

I'm doing some engineering analysis with the help of a FEA program and Python. When the analysis ends I need to press a key to continue. But this is not a normal press any key to continue. Every code executed with the scripts stops. Like a handput debug break. Nothing runs until I press something or switch windows.
I cant use send keys and subprocesses because running code completely stops. Only solution I could come up with is to use another script in another command window with simple send keys command. This extra script is useless if computer is used or another window is active.
I'm a beginner level programmer and maybe I'm missing something simple. I guess the problem is caused by the FEA programs code but I'm not sure. So is there any way to prevent my code from stopping? Thank you for your time.

It seems that the FEA program does the windowing and you cannot do much about it. I actually automate scripting in DIANA FEA. For this program I would try something like pywinauto.
https://github.com/pywinauto/pywinauto
And call your python script from another python script.
from pywinauto import Desktop, Application
import time
app = Application().start("FEA_program.exe my_python_script.py")
while True:
time.sleep(5)
# send key presses to the app every arbitrary seconds

Related

How do I avoid losing program focus after subprocess.call?

I am trying to extract data from a program; its raw data files are encrypted XMLs so my plan is to start the program, then use mouse control commands (e.g. pyautogui) to copy / paste the data.
So far I'm falling at the first hurdle; when I run subprocess.call to start the program, the program gets window focus and my subsequent code doesn't execute until I manually close the program.
workingFolder = self.get_working_folder() # get path where raw data is
subprocess.call('Path\Program.exe') # works, Program.exe starts
print(workingFolder) # this doesn't execute until I close the Program window
EDIT: After further testing I have answered my own question - subprocess.Popen was in fact what I needed, despite my initial doubts about it! Thanks to anyone who looked at my question :).
workingFolder = self.get_working_folder()
subprocess.Popen('Path\Program.exe')
print('This works')

Turn off echo of getpass.getpass() in IDLE

I would like to enter a password into the IDLE terminal in Windows without an echo.
Normally entering passwords is possible with python using the function getpass.getpass(), but in IDLE there comes up the following warning message:
GetPassWarning: Can not control echo on the terminal.
Warning: Password input may be echoed.
I found out, this is because IDLE replaces the sys.stdin with a different object:
if sys.stdin is not sys.__stdin__:
return fallback_getpass(prompt, stream)
However, I could not find a solution. Does anybody have an answer or another way to enter a password into the IDLE terminal without an echo?
As an IDLE maintainer with some familiarity with IDLE internals, I do not believe that it is possible to suppress character display but not otherwise change behavior in response to input('prompt') without major changes to IDLE code.
But even that would be insufficient for getpass.getpass since it calls one of unix_getpass, win_getpass, or default_getpass, and the first two use system_specific low-level functions that bypass stdin.
In terms of design intent: IDLE is, as its name says, a program development environment. Developed programs normally, and sometimes must be, executed by Python directly, without going through IDLE. Python normally runs attached to a terminal window. IDLE's Shell is based on a tkinter Text widget, which is a multiline editor, not a terminal. This is why one can enter, recall, and edit complete multiline statements rather than only a single line at a time.

Debugging non-responsive python/PyQt application in PyCharm

How do you go about debugging a non-responsive python/PyQt application in PyCharm?
I am an experienced programmer, but new to all thing python. I have been given a large application (36,000 lines), which works under Windows, to port to Linux.
Having made just a handful of changes for OS-specific stuff, when I run the application it comes up with its main window. But then after a few seconds it becomes dimmed, and when I close the window I am asked to confirm to end "the window is not responding".
(Aside: On a whim I decided to try running the app via sudo, and surprisingly it works fine. I have tried doing strace running as root versus non-root, but I'm fairly sure there is nothing obvious in the way of file accesses/permissions etc. that differs. This may be a clue, but just as likely to be a red-herring, e.g. if it's an "uninitialized variable".)
If I debug it inside PyCharm, at that point I expect to click the "Pause Program" button, so that I can get a trace back and begin to see where it is in the code, and start stepping or whatever. However, that button does nothing at this stage? Maybe it only "works" when on "a python instruction"?
If I force a core dump (from the keyboard) and examine with gdb, I can see that the stack frame shows it is way down inside libQtCore/libQtGui, in processEvents on a call to read.
So how do I begin to go about debugging why it is (presumably) busy doing something at this point, or at least not responding? Any tips would be welcome. I do hope this question will not fall foul of SO's "too general" policy, any tips to get someone going on debugging a "non-responsive" program would be welcome.
To answer my own question, since no responses seem to be forthcoming.
In this case, the problem turned out to lie in a file which is imported into other files, named pyperclip.py. That had code outside of any function, and in a path through the source executed under Linux but I think not under Windows, which included:
app = PyQt4.QtGui.QApplication([])
cb = PyQt4.QtGui.QApplication.clipboard()
Clearly some attempt to gain a clipboard object. For whatever reason, this appears to work when run as su, but when run as the logged on user it causes the whole application to "hang". Removing those two lines solved the unresponsiveness.
In terms of what I learnt from this for debugging unresponsive applications: you need to debug not from the entry point of the program, as I would have expected, but rather right from the start of each file, and actually step into each import line just in case it is executing some initial code. Horrible!

How to reenter Linux process after closing putty

I'm new to Linux.Yesterday I wrote some Python codes,now I'm using Linux to execute my codes,it may take a few hours. As my Linux is not native,it's a remote server,I use putty to connect to it.
Now ,I want to close putty and go to sleep.But I don't know how to find my process again and reenter it after I wake up and start putty.And also,I wrote some code to print progress rate,next time when I find the process,can I see the print info again?
Run screen, start your programm and close the connection. After logging in again, use screen -r to resume your session.
Alternatively nohup will do the trick.
screen is the best built-in tool that's always available for that, although it gets a bit weird around keyboard shortcuts, some of which sometimes don't work the way you want exactly.
I've found tmux to be much better in terms of usability.
Alternatively. take a look at mosh, which is trying to replace ssh. It's a mobile shell tool from MIT that supports intermittent connectivity, lots of praise there.

Clearing Python shell

How to clear Python shell ?
I am writing a module in python, I want to save it in a file. what is the best way to do it?
File -> New Window. Put your module in this new window, than save it. To run, just press F5.
Python shell does not get cleared or saved. Perhaps you are using IDLE. It's a confusing piece of software. I'd recommend you to get a real IDE, or at least a proper text editor.
Something that I do in IDLE is print "\n"*100
You can also extend Idle and map that to a key. Read Pythoninstall\lib\Idlelib\extend.txt for details
http://bytes.com/topic/python/answers/737111-extension-idle-clear-screen-but-how-write-screen
If you are just in console, you can do ( which won't work in IDLE):
import os
os.system("cls")
Just copy and paste the code into a new file (In file), and save it. To run, you can go to the run section and select "Run Module", or you can simply press F5.

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