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I decided recently that I want to start learning to code. I chose python as my first language because of it's versatility and Open Source connections. Now, of course to learn any programming language, first you have to be able to practice with it by writing code and running it.
I have Python beginner tutorials I am using but as soon as I got to the point where I wanted to run a simple Hello World message, I couldn't figure out how to get my document to actually RUN. I downloaded LiClipse with the hopes of using PyDev. I read that you can run a code directly from PyDev.
Wow, what a confusing mess! I downloaded the instant install version of LiClipse and I had to manually update the pip because it was out of date and that took an hour of research all on it's own to figure out how to do it.
Now that I have the interpreter set up correctly with the most recent pip...(I THINK), when I try to run any code I write, it doesn't let me. It wants me to save it first, which of course is quite logical. But when I try to save it, it says there is no folders to save to. How can there be no folders? I have been reading the install help, but it doesn't say anything about this issue. Or maybe it did explain how to fix this issue and I simply didn't understand all the jargon included in the configuration documentation. It kept instructing me to do technical things I couldn't understand.
Can anyone tell me what is going on? Shouldn't this all be ready to go when I used the "instant install" ?? I am just a beginner here, I don't know all this technical installation jargon. If anyone can help me get this setup, please let me know.
I really want to start learning. But I can't if I don't have the right tools.
Yeah, the technical jargon can be really confusing in the beginning. I've never heard of LiClipse but I can give you a few tips to get started:
Use a good IDE or Editor. For beginning VsCode with the Python PlugIn is quite good. You can also use PyCharm (the free version is enough) but that IDE is quite confusing.
Get comfortable with the commandline. On Windows you can invoke Python by running py on Linux with python3. You open the commandline on Windows by opening the startmenu, entering cmd and hitting enter.
You will have to make sure Python is in your "PATH" enviroment variable. That is a variable telling the Operating System where to find your programms. It should have asked you whether you want to add Python to your PATH during the install.
You run your python programm by saving it as a .py file and running py <filename.py> or python3 <filename.py> on Windows or linux respectively. You have to be in the directory where you saved your file of course.
I hope I could help you. Please mark this answer as accepted if it did answer your question or helped you with your issue.
I want to start by saying I'm mainly experienced in C & C++, not Python, but with programming in general many of the concepts carry over. I also don't have enough rep to comment, or I'd ask for some clarification on how familiar you are with the commandline.
I'm going to assume you're on Windows since you didn't mention the platform.
I wrote this like a tutorial, because I found those to be very helpful when I first started programming.
I can't recommend this enough, start off by using the commandline!
I think you complicated things more by searching for a text editor that can also run code. In order to get something like that working for your setup you need to know what's happening behind-the-scenes first.
Once you have a grasp of how to write & execute Python code, then you can move on to an IDE or advanced text editor like Visual Studio Code or LiClipse with confidence.
R+Click on the Start Menu, then click on Windows PowerShell to open a terminal.
Take a moment to note the filepath shown before the blinking cursor.
This is known as the Working Directory, which works similar to how the file explorer only allows you to "view" one directory at any given time; You can open multiple explorer windows side-by-side, but you can't view multiple directories at the same time in a single window.
You can run commands by typing them and pressing Enter.
You can also use the Tab key to autocomplete things like directory/file names, commands, etc. after typing a few characters.
Now let's create a workspace directory for your first project.
This can be anywhere that you choose, but for the sake of simplicity I'll be using my User directory which is usually where PowerShell will start by default.
To create a new directory named _workspace, use the mkdir (Make Directory) command like so:
mkdir _workspace
Now let's change our working directory to _workspace by using the cd (Change Directory) command like so:
cd _workspace
This directory is empty, but if you want to view the contents of a directory you can use the ls (List Directory) command:
ls
Since this is an empty directory, nothing will happen.
Next, we'll create a Python script file using the touch command, which creates empty files:
touch HelloWorld.py
Now that we have a script file, open HelloWorld.py in Notepad by running this command:
notepad HelloWorld.py
If you use a dark desktop theme, now is the time when your retinas may be seared out by the intensity of Notepad's white color scheme.
Now, let's add the code to print "Hello World!" in Python:
print("Hello World!")
Once you're done, you can save & close Notepad to save your retinas.
Now it's time to run the program! In the PowerShell window, enter this command:
py HelloWorld.py
which will show:
Hello World!
If you see an error saying this:
The term 'py' is not recognized as the name of a cmdlet, function, script file, or operable program.
You should re-install Python and make sure you check this box in the installer:
After re-installing Python and checking the Add to PATH box, close and reopen the PowerShell window, enter the cd _workspace command again, followed by py HelloWorld.py, which should be successful this time.
I hope I could be of some help, if so, I'd greatly appreciate marking this answer as accepted so I can write comments. Happy coding!
If you are using Linux following will work.
Install python3 first (Its better to stuck on python3 now. Once you get use-to then you can code in python2.7 also.)
Open a terminal, go the folder contains your code. If your source code is in hello.py then type python3 hello.py on terminal. It will execute and print the output on terminal.
The suggestions given by both #radj and #C. Dautermann are excellent.
Like others here, I will be assuming that you are on Windows.
Before jumping into LiClipse and PyDev, I highly recommend making sure that Python and packages (such as pip) are functioning on their own first. Command line is a great tool for this.
Windows Command Line can be accessed in a variety of ways, one of which is to go to your start menu and search "cmd." Command Prompt should return. In the command prompt, run the following:
python
This should return the version of Python installed on your machine if it is configured properly. For example, you may see the following:
Python 3.10.1 (...)[...] on win32
If this does not appear, I recommend uninstalling Python and reinstalling. In the installer, you will want to check the "Add Python ... to PATH" option. This will configure your environment variables on your machine. If you plan on running multiple versions of Python down the road, don't worry; you can use batch files to set the PATH variable to another version.
Once you have Python working, your command prompt will lead with the following:
>>>
Notice that there is no longer a file path followed by >>. This is because you are now in the Python interpreter. Congratulations!
To exit the Python interpreter, enter Ctrl+Z. It should appear as the following:
^Z
After we know Python works, we will check to see that pip works. Ensure you have pip installed by entering the following:
python -m pip --version
You should then be able to see the pip version. For example:
pip 22.0.3 from C:\...
If pip is not working, you can consult this documentation on pip to make sure pip gets installed properly.
Once pip is working, again, congratulations! You've gotten over some of the biggest hurdles. At this point, you can open up any text editor, type in:
print('Hello World!')
save the file with the extension .py, then run the script through command prompt. To run a script through the command line, you have to cd to the file location, then run the script with python, like so:
cd filepath
python filename.py
Where filepath is the path to the Python file and filename is the name of the file. For example:
cd C:\Users\name\Documents\PythonPractice
python helloworld.py
Usually, command line is all that is needed when starting out with Python outside of a text editor. Notepad comes standard on Windows computers, but there are plenty of other editors out there. Sublime text and Notepad++ are some of my favorites, personally.
Now, if you're able to run everything prior, the good news is that your Python and pip are both working, and you have everything you need to get started learning Python. If Python and/or pip are not functioning, there's thankfully a huge body of troubleshooting tips out there.
Unfortunately, from what I get of your initial post, you might be struggling with configuring LiClipse. I personally do not use LiClipse, nor do I use PyDev, so my help at this point may be limited. You may want to uninstall and reinstall after confirming your Python and pip work as a first step. After that, perhaps check that you are following the practices outlined in the LiClipse manual. Worst case scenario, you can try a different version of Python (I believe it has some Python3 incompatibilities), try running PyDev independent of LiClipse, or look at a different tool. If you believe the problem lies with file locations/existence, I would look at radj's post or play around in File Explorer to see what is going on for yourself.
Again, to get familiar with Python, you don't even need these extra tools. All you need is a text editor and the command line to get started.
Some other tools to help you get started:
PyPI
A venv virtual environment tutorial
PyDev
A comparison of LiClipse alternatives in case you continue to struggle
Hope this helps. Happy Coding!
If I accidentally entered a typo into a command prompt questionnaire, is there a way to go backwards and edit that input?
For example, when I run npm init, I'm given a bunch questions. If I accidentally write a typo in the package name field and press enter, the questionaire moves on to version:. Is there a way to quickly go back to package name and fix my typo?
My experience with the terminal and npm is limited, but I found out that you cannot undo a command line. However, I'm wonder if you CAN undo an answer to a command prompt, since this is a little different- The command hasn't really run yet until all the prompts are done.
Sat Apr 27 npm Dashie$ npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.
See `npm help json` for definitive documentation on these fields
and exactly what they do.
Use `npm install <pkg>` afterwards to install a package and
save it as a dependency in the package.json file.
Press ^C at any time to quit.
package name: (npm) oops-typo
version: (1.0.0)
An undo functionality like you are describing would have to be implemented by the developers of the cli tool you are using (in this case, npm).
I think the best I can offer as a means to fix your mistake on the command line, without having to open an editor and modify the package.json file from there, is to use the json npm package.
So in the particular case displayed in your question, you would keep going with the install and afterwards you could simply do:
$ npm i -g json
$ json -I -f package.json -e "this.name='your package name'"
You can edit the package name in the package.json file created when you use init.
Web development is new to me and I'm trying to grasp the meaning and usage of environment variables once and for all. In my research the most simple explanation I've come across is that it is comparable to 'configuration settings'.
Through the terminal I've been exploring what feels like the computer's innards by typing printenv etc etc.
But I'm still not sure when it is necessary to set up env var. For example, I use fish as my shell. Often when I try to do an npm install it seems like the package didn't take. Here is a recent example:
user#iMac-van-user ~/P/v/v/public_html> npm install -g modernizr
/usr/local/Cellar/node/10.4.0/bin/modernizr -> /usr/local/Cellar/node/10.4.0/lib/node_modules/modernizr/bin/modernizr
+ modernizr#3.6.0
updated 1 package in 2.316s
user#iMac-van-user ~/P/v/v/public_html> modernizr
When I try to use modernizr as a command fish will tell me the modernizr is an unknown command and the color remains red. Valid commands show up in white in fish. Thus I have a suspicion that modernizr will only be available and valid once I've set up the configs. I've had this happen many times with various attempts to install package managers and things like composer, vue-cli, etc. My failures to get it working boils down to my meager knowledge of environment variables and what they do, I think.
This is from the documentation on the modernizr site: modernizr -c modernizr-config.json
Note that you will need to give the command line config the file path
to the configuration you downloaded from the site. In the above
example, we are running the modernizr command from the same folder
that we downloaded the modernizr-config.json file to.
What does the sentence: "Note that you will need to give the command line config the file path to the configuration you downloaded from the site" imply? I copied the file into my project folder but there is no change.
Is there is someone that can explain the following to me in layman's terms, so like you would to a 5 year old, it would be great:
use of environment variables
setting up configs - why, where and how (I've done it once through VIM)
how to know when to set up environment variables
Thank you in advance.
Developing on macOS 10.
I was wondering if the following is possible.
I have a BASH script that I want to make available for some people but I wanted them to only have to "install" the program and not messing around with terminal, so I thought a .deb would be cool.
So what would the "install" do?
Simple. I want to move the script and an icon to a folder (any folder, but I was wondering some hidden folder in Home) and then run a script that creates a launcher in the Applications menu for the first script. It seems there isn't much to it, but for what I've searched, there doesn't seem to be a lot of info...
How can I accomplish this?
By the way, I'm using Ubuntu 11.04.
Basically (install and) run dh-make to set up the debian/ directory, edit the generated files (mainly remove the many you do not need, and fill in a package description and any dependencies in debian/control), then debuild-us -uc -b.
You may also have to set up a simple Makefile for debian/rules to call; it probably only needs an install target to copy the binary to $(DESTDIR)/usr/bin.
Binaries install into /usr/bin and you should not try to override that. The way to have a menu is to add a .desktop file.
Once you have a good .deb you will need to set up a repo for distributing it. The simplest solution is probably to set up a launchpad.net account and create a personal PPA there.
It's not hard to find more information on these topics, but of course, you need to know what to look for. The canonical documentation is the Debian New Maintainer's Guide.
Found this video on youtube that explains IN FULL the process of creating a *.deb for a script or program and even mentions how to do it for a C program.
Full guide in how to build simple *.deb package
Has one bug, btw, that the author, during the making of the *.deb, didn't notice. The path in the *.desktop file for the EXEC parameter is wrong in the example.
I'm trying to deploy my site using Fabric and Mercurial. In the Windows command line, running hg push works perfectly with no problems.
But when I try writing
local("hg push")
in a fabfile and running it, I get the error:
'"hg push"' is not recognized as an internal or external command, operable program or batch file.
Googling gave me an idea that it might be a problem with the PATH variable in Python subprocesses, for example here: Why would an "command not recognized" error occur only when a window is populated?.
Can you help me out? Is the bug in Fabric or in my own code?
Thanks.
As Chris R mentions, we don't do a ton of Windows support as none of the core devs are Windows users; we have to rely on reports and suggestions from our more savvy Windows users.
It sounds like this could be related to this recently fixed, but not released, bug -- it will be in Fabric 1.0.2 which should be out soon. If you're feeling brave, you can test it out now via:
pip install -e git+git://github.com/bitprophet/fabric#1.0#egg=Fabric
If you then do fab -V, it should say it's 1.0.2a -- if so, running your fabfile may work better. Please let us know if you do this!
It sounds like the you need to add Mercurial to the Fabric process's PATH.
Maybe something like:
fabric.context_managers.path(<path to your hg.exe>)
run('hg push')
See the docs for the path context manager. It wasn't clear if path applies to local commands, but run commands are explicitly referenced.
Neither of the fixes provided worked, but changing
local("hg push")
to
os.system("hg push")
solved the problem.