Develop Reference

Undo changes of '2to3' library

I had some python code in my SSH Project Folder which I had to convert from Python 2.7 to Python 3.*. Hence I installed the library 2to3.
However, before running the command 2to3 . -w, I navigated to the ROOT directory which contained all the Python and Conda relevant library files by mistake and ran my code from there.
So I think that has changed all the python files from the root directory and not just my project-specific files. Hence I am getting multiple errors now while running the code.
By any chance, is there any way to undo these changes? I tried conda update --all to upgrade my packages but nothing is happening. Is re-installing everything the only way to fix this?

Error checking for subterfuge update on Ubuntu

I am trying to run subterfuge on ubuntu. I downloaded and installed the latest software but when I try to run it I get this Message
Subterfuge courtesy of r00t0v3rr1d3 & 0sm0s1z
Checking for updates. You can disable this feature through the settings page.
sh: 1: /usr/share/subterfuge/manage.py: not found

I'm going to go out on a limb and guess that the file /usr/share/subterfuge/manage.py doesn't exist. This is likely because you installed subterfuge elsewhere on your machine.
Their source code has a number of hard-coded paths (for whatever reason) that require a specific installation directory.
I would copy your installation over to the directory in which they expect it to be
sudo cp -r /old/installation_dir/subterfuge/* /usr/share/subterfuge

Copy complete virtualenv to another pc

I have a virtualenv located at /home/user/virtualenvs/Environment. Now I need this environment at another PC. So I installed virtualenv-clone and used it to clone /Environment. Then I copied it to the other PC via USB. I can activate it with source activate, but when I try to start the python interpreter with sudo ./Environment/bin/python I get
./bin/python: 1: ./bin/python: Syntax Error: "(" unexpected
Executing it without sudo gives me an error telling me that there is an error in the binaries format.
But how can this be? I just copied it. Or is there a better way to do this? I can not just use pip freeze because there are some packages in /Environment/lib/python2.7/site-packages/ which I wrote myself and I need to copy them, too. As I understand it pip freeze just creates a list of packages which pip then downloads and installs.

Do the following steps on the source machine:
workon [environment_name]
pip freeze > requirements.txt
copy requirements.txt to other PC
On the other PC:
create a virtual environment using mkvirtualenv [environment_name]
workon [environment_name]
pip install -r requirements.txt
You should be done.
Other Resources:
How to Copy/Clone a Virtual Environment from Server to Local Machine

Pip Freeze Not Applicable For You?
Scenario: you have libraries installed on your current system that are very hard to migrate using pip freeze and am talking really hard, because you have to download and install the wheels manually such as gdal, fiona, rasterio, and then even doing so still causes the project to crash because possibly they were installed in the wrong order or the dependencies were wrong and so on.
This is the experience I had when I was brought on board a project.
For such a case, when you finally get the environment right you basically don't want to go through the same hell again when you move your project to a new machine. Which I did, multiple times. Until finally I found a solution.
Now, disclaimer before I move on:
I don't advocate for this method as the best, but it was the best for my case at the time.
I also cannot guarantee it will work when switching between different OSes as I have only tried it between Windows machine. In fact I don't expect it to work when you move from Windows to other OSs as the structure of the virtualenv folder from Unix-based OS is different from that of Windows.
Finally, the best way to do all of this is to use Docker. My plan is to eventually do so. I have just never used Docker for a non-web-app project before and I needed a quick fix as my computer broke down and the project could not be delayed. I will update this thread when I can once I apply Docker to the project.
THE HACK
So this is what I did:
Install the same base Python on your new machine. If you have 3.9 on the old, install 3.9 on the new one and so on. Keep note of where the executable can be located, usually something like C:\Users\User\Appdata\Local\Programs\Python\PythonXX
Compress your virtual env folder, copy it into the project directory
inside your new machine. Extract all files there
Using text editor of your choice, or preferably IDE, use the 'Search
in all files' feature to look for all occurrences of references to
your old machine paths: C:\Users*your-old-username*
Replace these with your new references. For my case I had to do it in
the following files inside the virtual env folder: pyvenv.cfg, Scripts/activate, Scripts/activate.bat, Scripts/activate.fish and Scripts/activate.nu.
And that's it!
Good luck everyone.

I think what occurs is that you just copy the symbolic links in the source file to the target machine as binary files(no longer links). You should copy it using rsync -l to copy to keep those links.

Usually I use virtualenv to create a new environment, then I go to the environment where I want to copy from, copy all the folders and paste it into the environment folder I just created, but most importantly when asking if you want to replace the Destination files, choose to skip these files. This way you keep your settings.
At least for me, this has worked very well.
I hope it works for you too.

I share my experience.
Suppose another PC does not install Python
Python version: 3.7.3
Platform: Platform: Windows 10, 7 (64bit)
The following is working for me.
Step:
download Windows embeddable zip file
download get-pip.py (because the embeddable zip file does not provide pip)
[Optional] install tkinter, see this article: Python embeddable zip: install Tkinter
Choose a packaging method (I use NSIS: https://nsis.sourceforge.io/Download)
folder artictures:
- main.nsi
- InstallData
- contains: Step1 & Step2
- YourSitePackages # I mean that packages you do not intend to publish to PyPI.
- LICENSE
- MANIFEST.in
- README.rst
- ...
- requirements.txt
- setup.py
The abbreviated content about main.nsi is as follows:
!define InstallDirPath "$PROGRAMFILES\ENV_PYTHON37_X64"
!define EnvScriptsPath "${InstallDirPath}\Scripts"
...
CreateDirectory "${InstallDirPath}" # Make sure the directory exists before the writing of Uninstaller. Otherwise, it may not write correctly!
SetOutPath "${InstallDirPath}"
SetOverwrite on
File /nonfatal /r "InstallData\*.*"
SetOutPath "${InstallDirPath}\temp"
SetOverwrite on
File /nonfatal /r "YourSitePackages\*.*"
nsExec::ExecToStack '"${InstallDirPath}\python.exe" "${InstallDirPath}\get-pip.py"' # install pip
nsExec::ExecToStack '"${InstallDirPath}\Scripts\pip.exe" install "${InstallDirPath}\temp\."' # install you library. same as: `pip install .`
RMDir /r "${InstallDirPath}\temp" # remove source folder.
...
/*
Push ${EnvScriptsPath} # Be Careful about the length of the HKLM.Path. it is recommended to write it to the HKCU.Path, it is difficult for the user path to exceed the length limit
Call AddToPath # https://nsis.sourceforge.io/Path_Manipulation
*/
hope someone will benefit from this.

Replacing a sourcecode inside an installed python package in Linux

I am really new to Linux system and I am currently using Ubuntu linux operation on Oracle VM VirtualBox. I have a few enquiries about using python and its packages.
This operation is already set up with python installed as well as one python package "pytopkapi". After I have modified one sourcecode in the original package, I would like to replace the old code in the installed package with this new one.
Then I typed,
help()
help> pytopkapi
and the screen shows:
Help on package pytopkapi:
NAME
pytopkapi
FILE
/usr/local/lib/python2.7/dist-packages/pytopkapi/__init__.py
I assumed that /usr/local/lib/python2.7/dist-packages/pytopkapi/ is the install directory and I did found the sourcecode I would like to replace. Then I copied the new sourcecode in to replace the old one. The whole process went alright but from the results, it seems like the new code is not used.
Could someone tell me if this is the right way to replace a sourcecode inside an installed python package? And if it's not, how can I do it?

Update:
After I seen those comments, I have deleted all .pyc file using:
sudo find . -name "*.pyc" -exec rm -rf {} \;
Make sure you have set up your work directory for the package folder specifically before you typed in the code!!!
I got this code from https://docs.python.org/2/install/, it will remove all pre-compiled python files under the work directory.
Then I have re-installed this package using:
sudo python setup.py install
Now if you run your original codes immediately, they might not be working, and say '... module cannot be found'. I just closed my python then reopen it. Everything just went alright.
Hope it can help.

Error packaging program in py2app

I have a program written in python 3.3 that I'd like to be able to distribute without the need for users to install python or any additional modules. I was able to successfully package this program using cx_Freeze on Windows, but the same script on OS X produced an app that wouldn't launch.
I thought I might have better luck using py2app, but now I'm running into a strange problem. The program opens (it has a GUI built with tkinter) and runs flawlessly when built in Alias mode. When I attempt to construct a final build, however, I get the following message in Terminal:
error: No such file or directory: /Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/setuptools-2.1-py3.3.egg/_markerlib/__init__.pyc
I navigated to that directory and found a .egg file that I'm unable to open or extract. I've tried reinstalling setup tools and well as python itself with no luck. Has anyone experienced this problem?

It looks like the problem is that your setuptools is somehow broken.
To open the egg file, I tried downloading a third party tool, which crashed, and renaming it as a .zip, which failed. If I just double click on it, I get the "choose default application" popup.
Double-clicking it relies on the extension to decide what app to launch.
The best way to check whether something is a valid zip file is to use the unzip tool from the command line. For example:
$ unzip -t setuptools.egg
This will check all of the zip headers, and check the CRC of all files in the archive, and report any errors. Or, if it's not a zip at all, it'll report one error right at the start.
You can also use the file command to do a quick check to see whether it's some well-known type of file. If file /path/to/setuptools-whatever.egg just says "data" instead of "Zip archive data", then it's probably corrupted beyond recognition.
Anyway, assuming your setuptools didn't come with your Python installation (if you're using a python.org binary installer, it didn't), the safest thing to do is uninstall it, then reinstall it cleanly.
The reason it's important to uninstall first is that the current version will, by default, not install a .egg archive, but will instead install a normal unzipped package and egg-info directory, meaning it may not overwrite the old, broken copy.
The documentation covers uninstalling. Just delete the setuptools .egg file, and anything else named setuptools*, from your site-packages (and anywhere else on your sys.path). If you have distribute there as well, kill that too. This will leave a few files sitting around in other places (notably easy_install-3.3 somewhere on your PATH), but they'll get overwritten properly by the installation, so that's OK.
To install, just follow the usual instructions to reinstall it:
$ wget https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py -O - | python
… or, if you don't have write access to site-packages:
$ wget https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py -O - | sudo python
If you use pip, you may want to reinstall it after reinstalling setuptools, and then pip install -U setuptools pip just to make sure you have the latest versions—and to verify that everything is now working.