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Python Readline on macOS behaves differently than on Linux/Windows

A project I'm working on uses a custom CLI handler instead of Python's cmd.Cmd class. Without getting too much in detail, the handler features TAB-key completion to assist the operator with command usage. The feature works as expected on Windows (using pyreadline) and Linux (using GNU's readline).
Here is an example of the expected behavior (assume "cmd > " is the prompt and that [TAB] is a push of the TAB key):
cmd > [TAB]
cd exit load save # all the available commands
cmd > c[TAB] # autocompletes to 'cd'
cmd > cd [TAB]
cd ./folder1 cd ./folder2 cd ./folder3 # folders in the cwd
cmd > cd C:\[TAB]
cd C:\Users cd C:\Windows... # enumerates folders in C:\ (on windows)
cmd > cd /[TAB]
cd /bin cd /opt cd /usr... # enumerates folders from root (on linux)
The custom class defines the following tab completion method, which is set using readline.set_completer():
def tab_completer(self, text, state):
# rl delims set to "" so we get the whole line as a single string
words = re.split(r'[\s\t\n]+', text)
# find_subcompleter populates a list of possible matches or next words
# each command implements its own completer_stub depending on the function (ex: cd will complete directory names)
retval = self.find_subcompleter(words.pop())
try:
return retval[state]
except IndexError:
return None
The function works as expected on Windows (10, Python 3.6.6) and Linux (CentOS 7, Python 3.6.8), but something strange happens on macOS (10.15.7, Python 3.8.2 via xcode on zsh terminal):
cmd > [TAB]
cd exit load save # this is good
cmd > c[TAB] # still autocompletes to 'cd', good
cmd > cd [TAB]
cd exit load save # as if I've typed nothing!
For those of you wondering, this behavior happens with ANY command, not just with cd.
I'm aware that the underlying readline implementation on macOS uses libedit due to GNU licensing. I just haven't seen anyone else (to date) mention this difference on any other forums. A possible solution that comes to mind is to add a conditional for libedit implementations to use get_line_buffer() and redisplay() to mimic the correct behavior. Any pointers in the right direction are appreciated!
Thank you

How do i run a python program just by typing the script name on windows 10 cmd line?

How do i run a python program just by typing the script name on windows 10 cmd line?
Also without having to change directory. I already added my scripts folder and python folder to the path.
tried also tu run assoc py.=PythonScript
ftype PythonScript=python.exe %1 %*
Here's the program's content:
#! python3
# mapIt.py - Launches a map in the browser using an address from the command line or clipboard
import webbrowser, sys, pyperclip
if len(sys.argv) > 1:
address = ' '.join(sys.argv[1:])
else:
address = pyperclip.paste()
webbrowser.open('https://www.google.com/maps/place/' + address)
I added a screenshot with all the commands i tried so far.

I think what you want is to run the file 'mapIt.py' without invoking the keyword python that is:
>mapIt.py
instead of
>python mapIt.py
the way to do that in Linux or macOS is simple enough, you can add
#!/usr/bin/env python
to the top of the file, rename your file from mapIt.py to mapIt
make the script executable:
chmod +x mapIt
But for windows there is no straightforward solution.
One way you can do it is convert the file into an exe or
first add a python.exe association for all '.py' files
> assoc .py=Python
and then
> ftype Python="<path of your python.exe>" "%1" %*
replace the text in angular brackets (<>) with the path of your python.exe file.

How do I make a python script executable?

How can I run a python script with my own command line name like myscript without having to do python myscript.py in the terminal?

Add a shebang line to the top of the script:
#!/usr/bin/env python
Mark the script as executable:
chmod +x myscript.py
Add the dir containing it to your PATH variable. (If you want it to stick, you'll have to do this in .bashrc or .bash_profile in your home dir.)
export PATH=/path/to/script:$PATH

The best way, which is cross-platform, is to create setup.py, define an entry point in it and install with pip.
Say you have the following contents of myscript.py:
def run():
print('Hello world')
Then you add setup.py with the following:
from setuptools import setup
setup(
name='myscript',
version='0.0.1',
entry_points={
'console_scripts': [
'myscript=myscript:run'
]
}
)
Entry point format is terminal_command_name=python_script_name:main_method_name
Finally install with the following command.
pip install -e /path/to/script/folder
-e stands for editable, meaning you'll be able to work on the script and invoke the latest version without need to reinstall
After that you can run myscript from any directory.

I usually do in the script:
#!/usr/bin/python
... code ...
And in terminal:
$: chmod 755 yourfile.py
$: ./yourfile.py

Another related solution which some people may be interested in. One can also directly embed the contents of myscript.py into your .bashrc file on Linux (should also work for MacOS I think)
For example, I have the following function defined in my .bashrc for dumping Python pickles to the terminal, note that the ${1} is the first argument following the function name:
depickle() {
python << EOPYTHON
import pickle
f = open('${1}', 'rb')
while True:
try:
print(pickle.load(f))
except EOFError:
break
EOPYTHON
}
With this in place (and after reloading .bashrc), I can now run depickle a.pickle from any terminal or directory on my computer.

The simplest way that comes to my mind is to use "pyinstaller".
create an environment that contains all the lib you have used in your code.
activate the environment and in the command window write pip install pyinstaller
Use the command window to open the main directory that codes maincode.py is located.
remember to keep the environment active and write pyinstaller maincode.py
Check the folder named "build" and you will find the executable file.
I hope that this solution helps you.
GL

I've struggled for a few days with the problem of not finding the command py -3 or any other related to pylauncher command if script was running by service created using Nssm tool.
But same commands worked when run directly from cmd.
What was the solution? Just to re-run Python installer and at the very end click the option to disable path length limit.
I'll just leave it here, so that anyone can use this answer and find it helpful.

Activating/deactivating virtualenv in a python script [duplicate]

I want to activate a virtualenv instance from a Python script.
I know it's quite easy to do, but all the examples I've seen use it to run commands within the env and then close the subprocess.
I simply want to activate the virtualenv and return to the shell, the same way that bin/activate does.
Something like this:
$me: my-script.py -d env-name
$(env-name)me:
Is this possible?
Relevant:
virtualenv › Invoking an env from a script

If you want to run a Python subprocess under the virtualenv, you can do that by running the script using the Python interpreter that lives inside virtualenv's /bin/ directory:
import subprocess
# Path to a Python interpreter that runs any Python script
# under the virtualenv /path/to/virtualenv/
python_bin = "/path/to/virtualenv/bin/python"
# Path to the script that must run under the virtualenv
script_file = "must/run/under/virtualenv/script.py"
subprocess.Popen([python_bin, script_file])
However, if you want to activate the virtualenv under the current Python interpreter instead of a subprocess, you can use the activate_this.py script:
# Doing execfile() on this file will alter the current interpreter's
# environment so you can import libraries in the virtualenv
activate_this_file = "/path/to/virtualenv/bin/activate_this.py"
execfile(activate_this_file, dict(__file__=activate_this_file))

The simplest solution to run your script under virtualenv's interpreter is to replace the default shebang line with path to your virtualenv's interpreter like so at the beginning of the script:
#!/path/to/project/venv/bin/python
Make the script executable:
chmod u+x script.py
Run the script:
./script.py
Voila!

It turns out that, yes, the problem is not simple, but the solution is.
First I had to create a shell script to wrap the "source" command. That said I used the "." instead, because I've read that it's better to use it than source for Bash scripts.
#!/bin/bash
. /path/to/env/bin/activate
Then from my Python script I can simply do this:
import os
os.system('/bin/bash --rcfile /path/to/myscript.sh')
The whole trick lies within the --rcfile argument.
When the Python interpreter exits it leaves the current shell in the activated environment.
Win!

To run another Python environment according to the official Virtualenv documentation, in the command line you can specify the full path to the executable Python binary, just that (no need to active the virtualenv before):
/path/to/virtualenv/bin/python
The same applies if you want to invoke a script from the command line with your virtualenv. You don't need to activate it before:
me$ /path/to/virtualenv/bin/python myscript.py
The same for a Windows environment (whether it is from the command line or from a script):
> \path\to\env\Scripts\python.exe myscript.py

Just a simple solution that works for me. I don't know why you need the Bash script which basically does a useless step (am I wrong ?)
import os
os.system('/bin/bash --rcfile flask/bin/activate')
Which basically does what you need:
[hellsing#silence Foundation]$ python2.7 pythonvenv.py
(flask)[hellsing#silence Foundation]$
Then instead of deactivating the virtual environment, just Ctrl + D or exit. Is that a possible solution or isn't that what you wanted?

The top answer only works for Python 2.x
For Python 3.x, use this:
activate_this_file = "/path/to/virtualenv/bin/activate_this.py"
exec(compile(open(activate_this_file, "rb").read(), activate_this_file, 'exec'), dict(__file__=activate_this_file))
Reference: What is an alternative to execfile in Python 3?

The child process environment is lost in the moment it ceases to exist, and moving the environment content from there to the parent is somewhat tricky.
You probably need to spawn a shell script (you can generate one dynamically to /tmp) which will output the virtualenv environment variables to a file, which you then read in the parent Python process and put in os.environ.
Or you simply parse the activate script in using for the line in open("bin/activate"), manually extract stuff, and put in os.environ. It is tricky, but not impossible.

For python2/3, Using below code snippet we can activate virtual env.
activate_this = "/home/<--path-->/<--virtual env name -->/bin/activate_this.py" #for ubuntu
activate_this = "D:\<-- path -->\<--virtual env name -->\Scripts\\activate_this.py" #for windows
with open(activate_this) as f:
code = compile(f.read(), activate_this, 'exec')
exec(code, dict(__file__=activate_this))

I had the same issue and there was no activate_this.py in the Scripts directory of my environment.
activate_this.py
"""By using execfile(this_file, dict(__file__=this_file)) you will
activate this virtualenv environment.
This can be used when you must use an existing Python interpreter, not
the virtualenv bin/python
"""
try:
__file__
except NameError:
raise AssertionError(
"You must run this like execfile('path/to/active_this.py', dict(__file__='path/to/activate_this.py'))")
import sys
import os
base = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
if(sys.platform=='win32'):
site_packages = os.path.join(base, 'Lib', 'site-packages')
else:
site_packages = os.path.join(base, 'lib', 'python%s' % sys.version[:3], 'site-packages')
prev_sys_path = list(sys.path)
import site
site.addsitedir(site_packages)
sys.real_prefix = sys.prefix
sys.prefix = base
# Move the added items to the front of the path:
new_sys_path = []
for item in list(sys.path):
if item not in prev_sys_path:
new_sys_path.append(item)
sys.path.remove(item)
sys.path[:0] = new_sys_path
Copy the file to the Scripts directory of your environment and use it like this:
def activate_virtual_environment(environment_root):
"""Configures the virtual environment starting at ``environment_root``."""
activate_script = os.path.join(
environment_root, 'Scripts', 'activate_this.py')
execfile(activate_script, {'__file__': activate_script})
activate_virtual_environment('path/to/your/venv')
Refrence: https://github.com/dcreager/virtualenv/blob/master/virtualenv_support/activate_this.py

You should create all your virtualenvs in one folder, such as virt.
Assuming your virtualenv folder name is virt, if not change it
cd
mkdir custom
Copy the below lines...
#!/usr/bin/env bash
ENV_PATH="$HOME/virt/$1/bin/activate"
bash --rcfile $ENV_PATH -i
Create a shell script file and paste the above lines...
touch custom/vhelper
nano custom/vhelper
Grant executable permission to your file:
sudo chmod +x custom/vhelper
Now export that custom folder path so that you can find it on the command-line by clicking tab...
export PATH=$PATH:"$HOME/custom"
Now you can use it from anywhere by just typing the below command...
vhelper YOUR_VIRTUAL_ENV_FOLDER_NAME
Suppose it is abc then...
vhelper abc

Putting a python path on a windows machine

I am a mac user and have never really used a pc from the command line.
How would I add django-admin.py to my path, so I can type in
> django-admin.py startproject newproject.
I suppoed I'd need to do the following:
1 - Find the python executable `django-admin.py`
2 - Add it to my system path
3 - > ln -s PATH/TO/django-admin.py <my system path>
I know this is a very newbie question, but I'm having trouble 'getting started' on a new windows system to create a new django project.

Just follow this tutorial. You need to add its full path to 'path' variable.
http://www.computerhope.com/issues/ch000549.htm