You know what has worked for me really well on windows.
My Computer > Properties > Advanced System Settings > Environment Variables >
Just add the path as C:\Python27 (or wherever you installed python)
OR
Then under system variables I create a new Variable called PythonPath. In this variable I have C:\Python27\Lib;C:\Python27\DLLs;C:\Python27\Lib\lib-tk;C:\other-folders-on-the-path
This is the best way that has worked for me which I hadn't found in any of the docs offered.
EDIT: For those who are not able to get it, Please add
C:\Python27;
along with it. Else it will never work.
Answer from darren on Stack Overflowpython - How to add to the PYTHONPATH in Windows, so it finds my modules/packages? - Stack Overflow
windows - how to set PATH=%PATH% as environment in Python script? - Stack Overflow
Python and the PATH variable in Windows 10
how do I modify the system path variable in python script? - Stack Overflow
How do I add an environment variable in Pythonpath?
How do I create a Pythonpath variable?
Is SYS path the same as Pythonpath?
You know what has worked for me really well on windows.
My Computer > Properties > Advanced System Settings > Environment Variables >
Just add the path as C:\Python27 (or wherever you installed python)
OR
Then under system variables I create a new Variable called PythonPath. In this variable I have C:\Python27\Lib;C:\Python27\DLLs;C:\Python27\Lib\lib-tk;C:\other-folders-on-the-path
This is the best way that has worked for me which I hadn't found in any of the docs offered.
EDIT: For those who are not able to get it, Please add
C:\Python27;
along with it. Else it will never work.
Windows 7 Professional I Modified @mongoose_za's answer to make it easier to change the python version:
- [Right Click]Computer > Properties >Advanced System Settings > Environment Variables
- Click [New] under "System Variable"
- Variable Name: PY_HOME, Variable Value:C:\path\to\python\version
- Click [OK]
- Locate the "Path" System variable and click [Edit]
Add the following to the existing variable:
%PY_HOME%;%PY_HOME%\Lib;%PY_HOME%\DLLs;%PY_HOME%\Lib\lib-tk;
Click [OK] to close all of the windows.
As a final sanity check open a command prompt and enter python. You should see
>python [whatever version you are using]
If you need to switch between versions, you only need to modify the PY_HOME variable to point to the proper directory. This is bit easier to manage if you need multiple python versions installed.
You can update PATH using several methods:
import sys
sys.path += ["c:\\new\\path"]
print sys.path
or
import os
os.environ["PATH"] += os.pathsep + os.pathsep.join(["c:\\new\\path"])
print os.environ["PATH"]
Repost Yaron's answer but dropped the sys.path. As in his post's comment, sys.path is for module search, not command search. PATH is for command search.
import os
os.environ["PATH"] += os.pathsep + os.pathsep.join(["c:\\new\\path"])
print os.environ["PATH"]
Do you remember checking the box in the image shown below to add your Python installation to PATH in Windows 10?
Adding Python to PATHWell, I was curious! What if someone accidentally forgot to check that little radio button? What would be the possible recovery steps?
So I spent my evening yesterday uninstalling Python and re-installing to figure out a way to add Python to the PATH post-installation.
If you forget to add Python to the PATH variable, you won't be able to run Python in your command line.
You will get a message saying,
‘python' is not recognized as an internal or external command.
Here are the steps I used to add Python to the PATH variable in Windows 10.
-
Copy the directory to which Python is being installed.
-
Search for System Properties in the Search Bar.
-
Click on the "Environment Variables" button in System Properties.
-
Click on the "Path" variable and then click on "Edit".
-
Now here's the deal. Paste the directory path from Step 1 at the top of the list. You can use the "Move up" button to get it to the top. Now click on "Ok".
I found out that if you paste the path at the end, it still doesn't work. Can someone tell me why?
Anyways, if the steps are not clear to anyone, here is a visual guide containing images of every step, on my blog for achieving the above objective. If you are interested, do take a look.
While the accepted answer works for the OP's purposes, and while the second answer is correct for updating the python sys.path variable, I think, if the OP weren't able to use the accepted answer (because, say, there was a policy against modifying the OS PATH variable on build/test machines), something like this SO answer would be what they are looking for. Summarizing the simple case here, to change the OS PATH environment variable:
app_path = os.path.join(root_path, 'other', 'dir', 'to', 'app')
os.environ["PATH"] += os.pathsep + app_path
At least, this is what I was hoping to find when I read the question.
@unutbu has the right approach, but for what it's worth, @Joe Schmoe, if you ever need the info:
import sys
print sys.path
['.', '/usr/local/bin', '/usr/local/lib/python2.6/dist-packages',...]
sys.path.append('/home/JoeBlow/python_scripts')
print sys.path
['.', '/usr/local/bin', '/usr/local/lib/python2.6/dist-packages', '/home/JoeBlow/python_scripts',...]
sys.path is an array containing everything that was in your initiating script's PYTHONPATH variable (or whatever your shell's default PYTHONPATH is).