Adding Python Path on Windows 7

Question

I\'ve been trying to add the Python path to the command line on Windows 7, yet no matter the method I try, nothing seems to work. I\'ve used the set command, I\

Answer 1

I've had a problem with this for a LONG time. I added it to my path in every way I could think of but here's what finally worked for me:

1. Right click on "My computer"
2. Click "Properties"
3. Click "Advanced system settings" in the side panel
4. Click "Environment Variables"
5. Click the "New" below system variables
6. in name enter pythonexe (or anything you want)
7. in value enter the path to your python (example: C:\Python32\)
8. Now edit the Path variable (in the system part) and add %pythonexe%; to the end of what's already there

IDK why this works but it did for me.

then try typing "python" into your command line and it should work!

---

Edit:

Lately I've been using this program which seems to work pretty well. There's also this one which looks pretty good too, although I've never tried it.

Answer 2

Try adding this python.bat file to System32 folder and the command line will now run python when you type in python

python.bat

@C:\Python27\python.exe %*

Source:

https://github.com/KartikTalwar/dotfiles/blob/master/bat/python.bat

Answer 3

I just installed Python 3.3 on Windows 7 using the option "add python to PATH".

In PATH variable, the installer automatically added a final backslash: C:\Python33\ and so it did not work on command prompt (i tried closing/opening the prompt several times)

I removed the final backslash and then it worked: C:\Python33

Thanks Ram Narasimhan for your tip #4 !

Answer 4

When setting Environmental Variables in Windows, I have gone wrong on many, many occasions. I thought I should share a few of my past mistakes here hoping that it might help someone. (These apply to all Environmental Variables, not just when setting Python Path)

Watch out for these possible mistakes:

1. Kill and reopen your shell window: Once you make a change to the ENVIRONMENTAL Variables, you have to restart the window you are testing it on.
2. NO SPACES when setting the Variables. Make sure that you are adding the ;C:\Python27 WITHOUT any spaces. (It is common to try C:\SomeOther; C:\Python27 That space (␣) after the semicolon is not okay.)
3. USE A BACKWARD SLASH when spelling out your full path. You will see forward slashes when you try echo $PATH but only backward slashes have worked for me.
4. DO NOT ADD a final backslash. Only C:\Python27 NOT C:\Python27\

Hope this helps someone.

Answer 5

The following program will add the python executable path and the subdir Scripts (which is where e.g. pip and easy_install are installed) to your environment. It finds the path to the python executable from the registry key binding the .py extension. It will remove old python paths in your environment. Works with XP (and probably Vista) as well. It only uses modules that come with the basic windows installer.

# coding: utf-8

import sys
import os
import time
import _winreg
import ctypes

def find_python():
    """
    retrieves the commandline for .py extensions from the registry
    """
    hKey = _winreg.OpenKey(_winreg.HKEY_CLASSES_ROOT,
                           r'Python.File\shell\open\command')
    # get the default value
    value, typ = _winreg.QueryValueEx (hKey, None)
    program = value.split('"')[1]
    if not program.lower().endswith(r'\python.exe'):
        return None
    return os.path.dirname(program)

def extend_path(pypath, remove=False, verbose=0, remove_old=True,
                script=False):
    """
    extend(pypath) adds pypath to the PATH env. variable as defined in the
    registry, and then notifies applications (e.g. the desktop) of this change.
    !!! Already opened DOS-Command prompts are not updated. !!!
    Newly opened prompts will have the new path (inherited from the 
    updated windows explorer desktop)
    options:
    remove (default unset), remove from PATH instead of extend PATH
    remove_old (default set), removes any (old) python paths first
    script (default unset), try to add/remove the Scripts subdirectory 
        of pypath (pip, easy_install) as well
    """
    _sd = 'Scripts' # scripts subdir
    hKey = _winreg.OpenKey (_winreg.HKEY_LOCAL_MACHINE,
               r'SYSTEM\CurrentControlSet\Control\Session Manager\Environment',
               0, _winreg.KEY_READ | _winreg.KEY_SET_VALUE)

    value, typ = _winreg.QueryValueEx (hKey, "PATH")
    vals = value.split(';')
    assert isinstance(vals, list)
    if not remove and remove_old:
        new_vals = []
        for v in vals:
            pyexe = os.path.join(v, 'python.exe')
            if v != pypath and os.path.exists(pyexe):
                if verbose > 0:
                    print 'removing from PATH:', v
                continue
            if script and v != os.path.join(pypath, _sd) and \
               os.path.exists(v.replace(_sd, pyexe)):
                if verbose > 0:
                    print 'removing from PATH:', v
                continue
            new_vals.append(v)
        vals = new_vals
    if remove:
        try:
            vals.remove(pypath)
        except ValueError:
            if verbose > 0:
                print 'path element', pypath, 'not found'
            return
        if script:
            try:
                vals.remove(os.path.join(pypath, _sd))
            except ValueError:
                pass
            print 'removing from PATH:', pypath
    else:
        if pypath in vals:
            if verbose > 0:
                print 'path element', pypath, 'already in PATH'
            return
        vals.append(pypath)
        if verbose > 1:
            print 'adding to PATH:', pypath
        if script:
            if not pypath + '\\Scripts' in vals:
                vals.append(pypath + '\\Scripts')
            if verbose > 1:
                print 'adding to PATH:', pypath + '\\Scripts'
    _winreg.SetValueEx(hKey, "PATH", 0, typ, ';'.join(vals) )
    _winreg.SetValueEx(hKey, "OLDPATH", 0, typ, value )
    _winreg.FlushKey(hKey)
    # notify other programs
    SendMessage = ctypes.windll.user32.SendMessageW
    HWND_BROADCAST = 0xFFFF
    WM_SETTINGCHANGE = 0x1A
    SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, u'Environment')
    if verbose > 1:
        print 'Do not forget to restart any command prompts'

if __name__ == '__main__':
    remove = '--remove' in sys.argv
    script = '--noscripts' not in sys.argv
    extend_path(find_python(), verbose=2, remove=remove, script=script)

Answer 6

I organized my python environment variable like this under Win7 64-bit using cmd.

I set the variable PYTHONPATH via environment variable menue of windows and added %PYTHONPATH% to the PATH variable:

...;%PYTHONPATH%

The cmd shell expands the variable correctly to this:

C:\>echo %PYTHONPATH%
C:\python27;c:\python27\lib;C:\python27\scripts

Do not forget to restart cmd shell after changing PATH.