Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 10 months ago.
Improve this question
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 I downloaded the instant install version of LiClipse and I had to manually update the pip because it was out of date and that took an hour of research all on it's own to figure out how to do it.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!
I'm trying to use perlcassa perl package in Window app. I started make but it failed because of missing prerequisites like Thrift::XS and Tie::IxHash
Unfortunatelly such prerequisites are not available for Windows.
Any idea how to overcome this?
Or is there another Perl package for Cassandra that supports Windows?
Thanks,
Abed.
Using Cassandra command line solves the problem. It is easy, direct and no need for additional packages. i.e I wrote Cassadnra script and used -f option in Cassandra CLI to invoke it.
I just found out that RedHat provides this "Developer toolset" which allows me to install (and of course use) the most up-to-date gcc-4.7.2. I use it on Centos, but the process is the same.
Once installed, you can start a new bash session with this toolset enabled by issuing:
scl enable devtoolset-1.1 bash
That works all right. Now, could I somehow add this to my bashrc since this actually starts a new bash session? Or should I better place it inside my makefiles to avoid starting a new bash session. Would there be a way to issue this within a makefile?
I wrote a blog post on this subject because it started to come up a lot. If you would like to read it, you can find it here: http://developerblog.redhat.com/2014/03/19/permanently-enable-a-software-collection/
tl;dr
you can source /opt/rh/devtoolset-1.1/enable in your .bashrc or, for somewhat better solution you can include:
source /opt/rh/devtoolset-1.1/enable
export X_SCLS="`scl enable devtoolset-1.1 'echo $X_SCLS'`"
But definitely check out the post for more info.
Check the URL
http://preilly.me/2013/05/28/redhat-developer-toolset-1-1/
for more information, for example how to set the CC, CPP, CXX environment variables. Or check
http://people.centos.org/tru/devtools-1.1/
for the devtool-1.1 repository for CentOS.
This is sort of a followup to this thread--unfortunately I didn't make any progress at the time so I thought I would start over. I am consistently getting this in the debugging log (QtCreator 2.3.1, Qt 4.7.3, gdb 7.2):
A syntax error in expression, near 0'.\n"
295^error,msg="A syntax error in expression, near0'."
&"Python scripting is not supported in this copy of GDB.\n"
296^error,msg="Python scripting is not supported in this copy of GDB."
&"Python scripting is not supported in this copy of GDB.\n"
297^error,msg="Python scripting is not supported in this copy of GDB."
&"Python scripting is not supported in this copy of GDB.\n"
298^error,msg="Python scripting is not supported in this copy of GDB."
&"Undefined command: \"bbsetup\". Try \"help\".\n"
299^error,msg="Undefined command: \"bbsetup\". Try \"help\"."
dThe debugging helper library was not found at .
&"source /home/matt/QtSDK-4.7.3/pythongdb/gdb\n"
&"/home/matt/QtSDK-4.7.3/pythongdb/gdb:1: Error in sourced command file:\n"
&"Undefined command: \"\". Try \"help\".\n"
300^error,msg="/home/matt/QtSDK-4.7.3/pythongdb/gdb:1: Error in sourced command file:\nUndefined command: \"\". Try \"help\"."
&"Undefined command: \"bbsetup\". Try \"help\".\n"
301^error,msg="Undefined command: \"bbsetup\". Try \"help\"."
dThe debugging helper library was not found at .
302^done
<303set substitute-path /var/tmp/qt-src /usr/include
The specific problem is that without the debugging helper, I'm unable to see the contents of QStrings and many other data structures during the debugging process, which makes it much more time-consuming. The error messages above are symptomatic, the problem arises when gdb can't find the debugging helper.
Anyway, looking at the discussion referenced in the answer in the above thread, I hunted around for different versions of gdb on my system but each one of them produced the same error (with the path changed appropriately of course), including version 7.3.1 when I downloaded it. I've also located libDebuggingHelper.so, but sticking it in different places hasn't helped either. Lastly looking at ./configure --help for gdb, I didn't see any options for enabling/disabling python in the build. Anybody know how I can get this to work?
This site claims you need to configure GDB using
./configure --with-python
It's pretty clear from the error message that the GDB you built does not have python support compiled in.
In gdb/config.log look for messages like checking whether to use python and see why GDB decided to not use Python on your system.
Perhaps you need to install Python development packages?
Once you've configured GDB to use Python, an easy way to check whether Python support is properly compiled in is:
(gdb) python print "hello"
If that prints anything other than hello, you are still not where you want to be.
I solved the problem with
sudo apt-get install gdb-multiarch
Thanks to #Employed-Russian for allowing me to check if GDB indeed has python support.
I did have to use the syntax
(gdb) python print("Hello")
To get a proper response from python within GDB.
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.