I had no .bash_profile file so I created one and the only line in it is this:
YOUTUBE_API=someRandomString
In my .zshrc file the first line is this:
source ~/.bash_profile
And from the command line I can run this:
echo $YOUTUBE_API
Which gives me a correct output (my API key).
But when I try to do it in Python it returns None:
import os
print(os.environ.get('YOUTUBE_API'))
I'm running python version 3.9.4. Any idea why, and how I may fix it?
Thank you
You need
export YOUTUBE_API=someRandomString
Otherwise, the variable is available to the local shell, but not to any subprocesses.
It only depends on where you run your code from:
if the process the code runs in has the variable set, it shouldn't be None
if you run the code inside another process, you'll get None
Explanation:
Each process ID gets it's own environment, stored in /proc/<pid>/environ file, where its local non-exported variables get stored. this path gets deleted as soon as the process stops.
The only way to make this work is to either export the variable in the shell, before launch the program, or run YOUTUBE_API=someRandomString python <your python file>
Related
I am trying to retrieve the parameters set from the jenkins build into my python script, but am having trouble. I understand the parameters set from here:
Are set as env variables and all I have to do in python is do:
# Env variables
UPDATE_DATA = os.environ.get('update_data')
ALL_BUILDS = os.environ.get('all_builds')
However I am getting None for those values. When I do an echo of those parameters in my jenkins script before my python script runs, I could see them being printed out correctly. However, for some reason python does not see them. If I go manually into a terminal and export a variable and run my python script, it works.. So I'm completely lost here.
Jenkins server is running on linux. Using python 2.7
You can use the boolean variable like this:
Output:
It seems like when I ran the python script in the Jenkins config (not inside a file within my project) like how #souravatta suggested, it found the env variable. So that means the env variable Jenkins is setting, is on a different instance somehow (even though they are on the same computer, same user). I just did a workaround where I wrote the env variables to a file and then just read that file in my python script.
I have a bat file that sets some environment variables such as
#echo off
SET MY_ENV_VAR=C:\temp
I would like to run this bat file via Python and run other executables that depend on this environment variable bat sets. But even if the bat file runs, I cannot see the environment variables via Python
subprocess.call(['path_to_bat_file\file.bat'], shell = False)
print(os.environ['MY_ENV_VAR'])
I tried to set Shell to True and add other parameters I found on the internet but nothing was successfull. It gives KeyError on os.environ that MY_ENV_VAR is not found. When I run the bat file manually before running the python script, everything works as expected.
Any help is appreciated.
Thank you,
There is no way to change your environment from a child process. The end :)
But you can change the environment variable from within a script like,
import os
os.environ["MY_ENV_VAR"] = "C:\temp"
Background:
I'm using Windows. I know some of programming with python. I don't know much about batch, which I think I might need to do what I want.
I will show a example so it becomes more clear what I'm trying to do.
Example:
When using git, after you install it, you can call the git command from anywhere of your computer, you can execute git commands, like git init and this will create a git file in your current folder.
I don't know exactly how git works or what language they use but I want to do the same thing, create my own command that I can execute from anywhere in my computer after I "install" my program.
What I'm trying to do:
I want to make my own command and when I call it, it executes a python script.
e.g.
I install my program and it creates a command called myprogram and when I type myprogram in the command line, it's like if I typed python myprogram.py. And myprogram -someargument would be the same as python myprogram.py -someargument.
What I tried until now:
I'm searched for How to make a environment variable that runs Python script? but I never get exactly what I want, is always something like How do I set environment variable using Python script?.
Maybe I'm making the wrong question and the result I want are not showing?
I'm looking for a explanation on how to do this or at least a tutorial/guide.
Edit 1:
As UnholySheep said in the comments, it's not environment variable, its commands, so I changed the question even does what I want to know is the same thing.
Files you need:
First you need a python script (obviously) so I created a file called myprogram.py that have this simple line:
print("This should be from a command")
After you need to make a batch file, in my case I used a .cmd file called myprogram.cmd that have:
#ECHO OFF
python_directory\python.exe python_script_directory\myprogram.py %*
Configurations to make:
You need to set in PATH environment variable the location of the batch file batch_file_directory\myprogram.cmd
And now if you execute in the command line myprogram it will print This should be from a command.
You can also use .exe or .bat files.
Running on Ubuntu, I have a python script, written by someone else, which simply runs like this:
python cool_script.py command line args
However, this script needs some environment variables set before it can run. So I created exports.sh located in the same dir as the python script, which looks something like:
export ENV1='foo'
export ENV2='bar'
export ENV3='baz'
so running:
$source exports.sh
$python cool_script.py command line args
works great. However, my case is a bit more complex. I need to run this on several environments, where the values of ENV1,ENV2,ENV3 will have to be different. I also want to do some stuff to the outputs of cool_script.py. So I wrote cool_script_wrapper.py, which looks like this:
# set environment variables
import os
exports_file = os.path.dirname(os.path.realpath(__file__)) + '/exports.sh'
os.system('source %s' % exports_file)
# run cool_script.py
os.system('python cool_script.py command line args')
# do some stuff to the output
...
I was planning to have different exports.sh scripts for each environment I need to run on, always keeping them in the same dir as the main script. Only problem is that this 'source' approach doesn't work. The environment variables are simply not available to cool_script.py.
Searching around Stack Overflow, I understand now that it's not supposed to work, but I didn't find any solution that suits my needs. I don't want to use os.environ with hard-coded values, and I don't want to parse the exports file. I guess I could make my wrapper a bash script rather than a python, but I hope there is a better solution. Any ideas?
The problem is in the source command that attempts to call a bash builtin.
This should work:
import os
os.environ['ENV1'] = "foo"
os.system("python cool_script.py command line args")
compare with this answer:
Calling the "source" command from subprocess.Popen
I find that when I start the python shell I have a bunch of commands I always type to get into the state I want. It is tiresome to keep re-typing these commands, so I have bundled them into a script. Now I just type:
execfile('script.py')
as soon as I enter the shell, and it goes through all the steps to get me to the state I need to be in.
Now I'd like to take it one step further. How can I get the python shell to automatically run script.py every time I start the shell, so I don't have to keep re-typing even that one line?
Here's a way without having to mess with environment variables:
For example, if I had a script with the following in it called script.py:
#!/usr/bin/env python
print("example")
I could tell python to run this before bringing me to the interpreter with the -i flag.
$ python -i script.py
example
>>>
I think you're looking for the PYTHONSTARTUP environment variable
I'd suggest you to use IPython, if possible. It gives tones of great features, and autoexec is only one of them. But of course, correct answer is mentioned by #mgilston
Create a file called usercustomize.py, and place it in your USER_SITE directory (which you can find as import site; site._script(). This file will be executed every time you start an interpreter.
There's a similar file called sitecustomize.py which is executed anytime anyone starts Python.
This is a Windows solution, but I'm sure a Unix equivalent could be done. I created a file \MyPythonCode\autoexec.py (the last line of which is a print("Autoexec Complete")) and a BAT file MyPython.Bat which has:
cd \myPythonCode
python -i autoexec.py
I just use the command: mypython
to start the Python environment every time, now.