Is there a way to execute a file but still be able to call the variables? This would help immensely in learning Python, since I could set up many different "practice" scripts and then use the console to try and modify the code to see what happens.
I think the technical question would be "How can I populate a namespace in Python in Eclipse and leave it open to interactions in the console?
Below is a screenshot showing what I'm trying to do, define a (as 1) in the editor, and then press "ctrl-alt-enter" to run the file in the console, and then call the variable from the console.
[Screenshot of Eclipse]
You should be able to add a debugging breakpoint at the end of code you are executing and inspect variables using a good editor.
In general, you should be able to run simple scripts right inside a python interpreter. Or online if you wish to: http://www.datamech.com/devan/trypython/trypython.py
Try setting up a REPL (read-eval-print) environment using your favorite editor. For instance, emacs has good support for doing such tasks.
Related
I just started to code on Python, so I downloaded the "Python 3.10 (64-bit)". The problem is that it runs the code without my permission. For example, if I am trying to type in print("example") it just runs on it's own. This means I can't do an actual coding project, it just runs the 1 piece of code right after I hit the Enter button. I don't know if I'm just blind or it's obvious, but I can't figure it out. What do I do?
Hitting enter after you type is "giving permission" to run the code that is typed (or copied)...
You can still write "scripts" this way - you define variables, functions, classes, etc, and they remain in scope of the interactive session.
If you want to "code a project," though, you should use an external IDE such as Visual Studio Code, PyCharm, Spyder, etc. The built-in IDLE is very basic, but still does allow for file execution.
Where do you write your code?
If you are using the command line, you cannot do anything to change this; you have to use a file with the extension ".py", for example "first_file.py", and write the code inside that file. When you are done or when you want to test your code, you have to open the terminal in the file folder and type python [filename].py and after that, your code will be compiled and executed in the terminal. I recommend using a code-writing program like VS Code, Atom or something like that.
So I am relatively new to programming and used to use Python's own "IDLE". After I run a ".py" file with IDLE, I am used to getting a python shell or a command window, I don't really know the terminological name for it, where I could play around with the objects inside the script.
For example, if I had a list A=[1,2,3] inside the program, after I run it I get a command console that says ">>" and I can say ">>A" which gives me "[1,2,3]" and I can add elements to A etc.
Now, I want to start using VS Code but I can't seem to find that particular thing. I have a terminal where I can run python code if I give the command "python" first, but It doesn't seem to effect anything inside the script.
I want to use that to see if some objects are working fine and to check their types etc. I add more lines to code after I try from there first, if that makes sense.
Sorry for really bad terminology, I really don't know the names but I can try even more if it's not clear.
Thanks a lot in advance.
Are you looking for the Integrated Terminal of VS Code?
Here are some ways to open the terminal:
Use the ⌃` keyboard shortcut with the backtick character.
Use the View > Terminal menu command.
From the Command Palette (⇧⌘P), use the View: Toggle Integrated Terminal command.
In the window that shows up, enter python and you'll get the Python shell you're looking for.
Try using the integrated terminal inside vs code and make sure that python and pip are properly configured. Type python in the command line and make sure the terminal points to the same folder where your program file is located.
I am writing Python scripts in Pycharm with IPython installed. So I can use Python Console in Pycharm to type Python commands and check the immediate output of the codes. However, when I run a script file after pressing 'Run' button (Shift+F10), all the variables and functions are not visible to the Python Console. This is, however, the feature of Spyder, another popular Python IDE. So here is my question: how can I configure Pycharm so that running a Python script file is visible for Python Console? Thanks
You could also run the part of your code you want to test/check in the console by selecting it and then right clicking and clicking on "Execute Selection in Console Alt-Shift-E". That's what I use sometimes when the debugger is not helpful. After running the code (you can also just "run" functions or classes) the console knows the functions and you can use the same features that Spyder has. However, be aware that when you change the code you need to run it in the console once to update the console definitions!
You can not. But you can use pdb (which will break code execution where you need it and you will be able to do the same things, as in the Python Console).
And, which is better and more powerful, you can use PyCharm's debugger. It represents all available variables in tree-like structures and is really handy.
I'm using visual studio code with standard python extension, my issue is that when I run the code the python interpreter instantly closes right after and I only see the output which means that if I create some data structure I have to create it every single time. Is it possible to leave the console open after running the code and maybe running multiple files in the same python interpreter instance?
I used to use spyder which is entirely doing what you want (probably like PyCharm)...
Then I briefly tried VS Code, and it is quite easy to make it behave that way too.
First make sure you have an integrated terminal open (or do Ctrl+`, or View > Integrated Terminal), then in that terminal launch ipython.
Now, when you use the commands from Don Jayamanne's Python extension (Ctrl+Shift+P to open commands palette):
"Run Python File in terminal"
"Run select/line in Terminal"
It will run the line inside the ipython console directly. So running the entire file will call python module.py inside ipython, and thus fails.
So to make this work simply create settings to map which command is executed when "Run select/line in terminal":
Open Language specific settings (Shift+Ctrl+P, search "Configure Language specific Settings...")
Pick up Python
Now I would suggest to make change only in your workspace settings (top-right tab) to keep default behaviour in other cases
so add in WORKSPACE SETTINGS:
(keep in mind it is just a simple/stupid workaround)
{
"python.pythonPath": "run"
}
Now when runing whole file, it will use ipython function run within the ipython terminal that we launched, thus keeping all your workspace variables.
Also, if you run some line of code with "Run Select/Line in Terminal", the ipython session of that terminal keep all variables.
This allows live debugging, without actually going in the debug mode.
When you run a program, it runs until it ends. Then it closes. If you want it to stay live longer, you can make a program which does not stop until told so, e.g.
while True:
something = raw_input('Write something: ')
print('You wrote: %s' % something)
if something == 'bye':
print 'bye.'
break
This will run until user writes "bye".
I'm quite late to this conversation, but a workaround I use is to put a pass statement at the end of my file, then add a breakpoint to it. I then run it in the debugger and can access all of the variables etc.
This allows most of the functionality that I used to use in the PyCharm python terminal, such as exploring data structures, checking out methods, etc. Just remember that, if you want to make a multi-line statement (eg. for a loop), you need to use Shift-Enter to go to the next line otherwise it'll try to evaluate it immediately.
How can you save functions/ classes you've writing in a python interactive session to a file? Specifically, is there a way in pydev / eclipse's interactive session (on a mac) to do this?
I just started learning python - and am enjoying using the interpreter's interactive session for testing and playing with modules I've written. However, I find myself writing functions in the interpreter, which I think, oh it would be cool to save that to my script files. How do I do this?
I tried:
import pickle
pickle.dump(my_function, open("output.p", "w"))
But it seems to be more of a binary serialization, or at least nothing that I could copy and paste into my code...
Are there ways to see the code behind classes & functions I've defined in the interpreter? And then copy them out of the interpreter?
Update:
Ok, here's what I've learned so far:
I missed the easiest of all - PyDev's interactive session in eclipse allows you to right click and save your session. Still have to remove >>>'s, but gets the job done.
IPython is apparently the way to go to do this.
How to save a Python interactive session? has more details.
The best environment for interactive coding sessions has to be IPython, in my opinion. It's built on and extends the basic Python interpreter with a lot of magic, including history. For example, you can issue the command %logstart to dump all subsequent input to a file, which still needs to be edited afterward before it will be a script, but gives you a lot to work with.
When installing IPython, don't forget pyreadline.
In general, however, it is best to write code in an IDE and then run it. IPython helps here as well. If you write and save the script, then use the IPython "run" command to run it, the entire global namespace of the script will be available for inspection in your IPython session. Additionally, you can use the -d argument to run to trigger the pdb debugger immediately on any unhandled exception.
If you're more of a straightlaced IDE and debugger kind of guy, then the easiest and best lightweight environment has to be PyScripter.
I think the answer is to change your workflow.
What I do is write my functions in an editor (emacs), and then press a key combination (Ctrl-c Ctrl-e) to send the region of text to the (i)python interpreter.
That way I can save the function if I want, and also play with it in an interpreter.
Emacs is central to how I do it, but I'm sure there must be similar approaches with many editors (vim, gedit, etc) and IDEs.
PS. Finding a good editor is crucial when working with Python. The editor must be able to move blocks of code to the left and right easily, or the whitespace issue becomes too onerous.
I dislike typing blocks of code in the python interpreter because it doesn't allow me to shift blocks easily. You'll like Python even more when you find the right editor.
You can setup a python history file which stores everything you type into the interpreter.
Here's how:
http://docs.python.org/tutorial/interactive.html
I think it can't be done.
Python can perform instrospection with the inspect module, but the inspect.getsource function won't work without a source file.