Disclaimer: Sorry if the question is stupid or repeated, I've tried to find similar ones that answer what I need to know but I couldn't. I've started to learn programming about 1 month ago and this is my second time on this website. Feel free to point out any errors or better ways to formulate my questions on stackoverflow, I'll be grateful.
Context:
I was trying to find out a way to print a string - in this case ' º ' - after my user's input - an angle -, on the same line.
I need an alternative way to do this, or help with the one I'm using.
What I got from my research is that, apparently, using the command os.system(cls) should erase the previous line, and putting \033[A before the string should move the cursor up one line. So using these two together should erase the previous line and then overwrite it.
Here's my try:
from os import system
cls = lambda: system('cls')
angle = float(input(f'Insert an angle:'))
cls()
print(f'\033[AInsert an angle:{angle}º')
Desired result on run:
Insert an angle: *60*º # being 60 the user's input
Actual result on pycharm:
Insert an angle:60
Insert an angle:60.0º # for some reason, you can't see it when paste it here, but there's a symbol of a crossed rectangle on the beginning of this line on Pycharm's run
How it looks on pycharm's run terminal
As you can see, the line isn't getting overwritten, only repeated.
What is weird is that when I run this program with Python 3.8 instead of Pycharm, it works as intended, but, on Pycharm, the line isn't overwritten. Instead, Pycharm just prints a crossed rectangle symbol.
Why does it work when executing the file with Python 3.8, but not when pressing "run" on pycharm?
Is there a way to avoid it?
Are there better alternatives to printing a string on the same line as an input?
In cases where I need special printing (ANSII escape codes, backspacing...), I use the actual Terminal, not the Python Console.
For whatever reason, interactive consoles, regardless of IDE, seem to have issues with handing specialties like that. With the normal Terminal, it works as expected:
I have never found a way of having the interactive console handle cases like this.
Relevant background information
I'm not asking for any technical coding advice but how to use an IDE as
i've seen to encounter some sort of bug or of turned something on.
I'm coding Object-Oriented python in it's basic editor: Idle.
Problem
When I enter a new line, it doesn't tab back where relevant anymore
but where I was in the previous line, but in the next one.
Sometimes it goes even farther.
What I've tried to do
I looked everywhere on IDLE if it was some sort of option I've accidentally
turned on. I've restarted IDLE completely multiple times.
What I'm asking for
Does any python programming know what this is and how to turn it off.
I am new to python programming... Just wanted to know does IDLE has a concept of 'executing selected statements'??
F5 runs the whole program... Is there any way to do this?
No, not now. Since you are at least the second person to ask this, I added the idea to my personal list of possible enhancements. However, while running a selection would not be a problem, producing accurate tracebacks for exception would be. Doing so is an essential part of Python's operation.
Currently, one can disable code that you need to not run by commenting it out (Alt-F3) or by making it a string. One can stop execution after a particular statement by adding 1/0. Or you can copy code to a new editor window.
Do you have a specific use case in mind, or are you just wondering?
Install Spyder, with its dependecies, and you will have wonderful FREE IDE !
You will have another solution, is to use IPython Notebook, where you will be able to use your Internet Browser to run python codes!:
I would like to make a Python script for Linux that brings up a prompt, allows the user to enter some keystrokes, and then prints a special character into whatever GUI-based program/widget happens to have the focus after my Python script exits (which takes the focus after the prompt goes away). Note that 'whatever program I happen to be using' is not particularly a program I made myself.
Is this possible? If so, how?
I know how to make a prompt, do keybindings and all that. I know how to use both xclip and xsel to copy stuff to the clipboard and I imagine paste, too (though I haven't had the need to paste with them, before). Is there a way to use them or something else to paste into the program that has the focus after my program (as opposed to merely pasting into my program)?
Basically, I'm trying to simulate the compose key with a Python program because the compose key doesn't always work, anymore, on Xubuntu 14.04 for some reason (just sometimes, and temporarily). It worked fine in previous versions all the time. If I had a Python program that could do this, then I wouldn't have to worry about whether the compose key would work on any future Xubuntu versions.
Well, I found the answer before I was done asking.
sudo apt-get install xautomation
xte 'keydown Alt_L' 'key Tab' 'keyup Alt_L' 'keydown Control_L' 'usleep 200000' 'key v' 'keyup Control_L'
You can surmise the rest. I just need to have Python execute the xte command above after I enter the keystrokes.
I wrote something here that might be helpful for this:
https://github.com/gvb1234/simulate-compose-key
it intercepts the Multi_Key if the focus is in a particular app, and does some fancy things with the next few keys, if they form a valid compose sequence.
This could be easily modified to call xdotool (or directly from python) to send the proper utf8 character to the window in focus.
I'm trying to run an external, separate program from Python. It wouldn't be a problem normally, but the program is a game, and has a Python interpreter built into it. When I use subprocess.Popen, it starts the separate program, but does so under the original program's Python instance, so that they share the first Python console. I can end the first program fine, but I would rather have separate consoles (mainly because I have the console start off hidden, but it gets shown when I start the program from Python with subprocess.POpen).
I would like it if I could start the second program wholly on its own, as though I just 'double-clicked on it'. Also, os.system won't work because I'm aiming for cross-platform compatibility, and that's only available on Windows.
I would like it if I could start the second program wholly on its own, as though I just 'double-clicked on it'.
As of 2.7 and 3.3, Python doesn't have a cross-platform way to do this. A new shutil.open method may be added in the future (possibly not under that name); see http://bugs.python.org/issue3177 for details. But until then, you'll have to write your own code for each platform you care about.
Fortunately, what you're trying to do is simpler and less general than what shutil.open is ultimately hoped to provide, which means it's not that hard to code:
On OS X, there's a command called open that does exactly what you want: "The open command opens a file (or a directory or URL), just as if you had double-clicked the file's icon." So, you can just popen open /Applications/MyGame.app.
On Windows, the equivalent command is start, but unfortunately, that's part of the cmd.exe shell rather than a standalone program. Fortunately, Python comes with a function os.startfile that does the same thing, so just os.startfile(r'C:\Program Files\MyGame\MyGame.exe').
On FreeDesktop-compatible *nix systems (which includes most modern linux distros, etc.), there's a very similar command called xdg-open: "xdg-open opens a file or URL in the user's preferred application." Again, just popen xdg-open /usr/local/bin/mygame.
If you expect to run on other platforms, you'll need to do a bit of research to find the best equivalent. Otherwise, for anything besides Mac and Windows, I'd just try to popen xdg-open, and throw an error if that fails.
See http://pastebin.com/XVp46f7X for an (untested) example.
Note that this will only work to run something that actually can be double-clicked to launch in Finder/Explorer/Nautilus/etc. For example, if you try to launch './script.py', depending on your settings, it may just fire up a text editor with your script in it.
Also, on OS X, you want to run the .app bundle, not the UNIX executable inside it. (In some cases, launching a UNIX executable—whether inside an .app bundle or standalone—may work, but don't count on it.)
Also, keep in mind that launching a program this way is not the same as running it from the command line—in particular, it will inherit its environment, current directory/drive, etc. from the Windows/Launch Services/GNOME/KDE/etc. session, not from your terminal session. If you need more control over the child process, you will need to look at the documentation for open, xdg-open, and os.startfile and/or come up with a different solution.
Finally, just because open/xdg-open/os.startfile succeeds doesn't actually mean that the game started up properly. For example, if it launches and then crashes before it can even create a window, it'll still look like success to you.
You may want to look around PyPI for libraries that do what you want. http://pypi.python.org/pypi/desktop looks like a possibility.
Or you could look through the patches in issue 3177, and pick the one you like best. As far as I know, they're all pure Python, and you can easily just drop the added function in your own module instead of in os or shutil.
As a quick hack, you may be able to (ab)use webbrowser.open. "Note that on some platforms, trying to open a filename using this function, may work and start the operating system’s associated program. However, this is neither supported nor portable." In particular, IIRC, it will not work on OS X 10.5+. However, I believe that making a file: URL out of the filename actually does work on OS X and Windows, and also works on linux for most, but not all, configurations. If so, it may be good enough for a quick&dirty script. Just keep in mind that it's not documented to work, it may break for some of your users, it may break in the future, and it's explicitly considered abuse by the Python developers, so I wouldn't count on it for anything more serious. And it will have the same problems launching 'script.py' or 'Foo.app/Contents/MacOS/foo', passing env variables, etc. as the more correct method above.
Almost everything else in your question is both irrelevant and wrong:
It wouldn't be a problem normally, but the program is a game, and has a Python interpreter built into it.
That doesn't matter. If the game were writing to stdout from C code, it would do the exact same thing.
When I use subprocess.Popen, it starts the separate program, but does so under the original program's Python instance
No it doesn't. It starts an entirely new process, whose embedded Python interpreter is an entirely new instance of Python. You can verify that by, e.g., running a different version of Python than the game embeds.
so that they share the first Python console.
No they don't. They may share the same tty/cmd window, but that's not the same thing.
I can end the first program fine, but I would rather have separate consoles (mainly because I have the console start off hidden, but it gets shown when I start the program from Python with subprocess.POpen).
You could always pipe the child's stdout and stderr to, e.g., a logfile, which you could then view separately from the parent process's output, if you wanted to. But I think this is going off on a tangent that has nothing to do with what you actually care about.
Also, os.system won't work because I'm aiming for cross-platform compatibility, and that's only available on Windows.
Wrong; os.system is available on "Unix, Windows"--which is probably everywhere you care about. However, it won't work because it runs the child program in a subshell of your script, using the same tty. (And it's got lots of other problems—e.g., blocking until the child finishes.)
When I use subprocess.Popen, it starts the separate program, but does so under the original program's Python instance...
Incorrect.
... so that they share the first Python console.
This is the crux of your problem. If you want it to run in another console then you must run another console and tell it to run your program instead.
... I'm aiming for cross-platform compatibility ...
Sorry, there's no cross-platform way to do it. You'll need to run the console/terminal appropriate for the platform.