Ask for admin access for a Python function in Windows

Question

I want to copy a list of files to the Windows system directory (C:\Windows) using a Python function.

I have a function:

import shutil

def copy_list(src_list, dst):
    for file in src_list:
        shutil.copy(file, dst)

And I want to call it like this:

def copy_as_admin():
    #... some code to obtain user elevation ...

    copy_list(files_list, "C:\\Windows\")

How can I achieve this? PS: I'm using Python3, I tried solutions in this thread, How to run python script with elevated privilege on windows but those solutions are for Python version 2.

Answer 1

You can now use the PyUAC module (for Windows). It works for me (I'm using Python 3). Install it using:

pip install pyuac
pip install pypiwin32

Direct usage of the package is:

import pyuac

def main():
    print("Do stuff here that requires being run as an admin.")
    # The window will disappear as soon as the program exits!
    input("Press enter to close the window. >")

if __name__ == "__main__":
    if not pyuac.isUserAdmin():
        print("Re-launching as admin!")
        pyuac.runAsAdmin()
    else:        
        main()  # Already an admin here.

Or, if you wish to use the decorator:

from pyuac import main_requires_admin

@main_requires_admin
def main():
    print("Do stuff here that requires being run as an admin.")
    # The window will disappear as soon as the program exits!
    input("Press enter to close the window. >")

if __name__ == "__main__":
    main()

The actual code (in the module) is:-

#!/usr/bin/env python
# -*- coding: utf-8; mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
# vim: fileencoding=utf-8 tabstop=4 expandtab shiftwidth=4

# (C) COPYRIGHT © Preston Landers 2010
# Released under the same license as Python 2.6.5

 
import sys, os, traceback, types
 
def isUserAdmin():
   
    if os.name == 'nt':
        import ctypes
        # WARNING: requires Windows XP SP2 or higher!
        try:
            return ctypes.windll.shell32.IsUserAnAdmin()
        except:
            traceback.print_exc()
            print "Admin check failed, assuming not an admin."
            return False
    elif os.name == 'posix':
        # Check for root on Posix
        return os.getuid() == 0
    else:
        raise RuntimeError, "Unsupported operating system for this module: %s" % (os.name,)
   
def runAsAdmin(cmdLine=None, wait=True):
 
    if os.name != 'nt':
        raise RuntimeError, "This function is only implemented on Windows."
   
    import win32api, win32con, win32event, win32process
    from win32com.shell.shell import ShellExecuteEx
    from win32com.shell import shellcon
   
    python_exe = sys.executable
 
    if cmdLine is None:
        cmdLine = [python_exe] + sys.argv
    elif type(cmdLine) not in (types.TupleType,types.ListType):
        raise ValueError, "cmdLine is not a sequence."
    cmd = '"%s"' % (cmdLine[0],)
    # XXX TODO: isn't there a function or something we can call to massage command line params?
    params = " ".join(['"%s"' % (x,) for x in cmdLine[1:]])
    cmdDir = ''
    showCmd = win32con.SW_SHOWNORMAL
    #showCmd = win32con.SW_HIDE
    lpVerb = 'runas'  # causes UAC elevation prompt.
   
    # print "Running", cmd, params
 
    # ShellExecute() doesn't seem to allow us to fetch the PID or handle
    # of the process, so we can't get anything useful from it. Therefore
    # the more complex ShellExecuteEx() must be used.
 
    # procHandle = win32api.ShellExecute(0, lpVerb, cmd, params, cmdDir, showCmd)
 
    procInfo = ShellExecuteEx(nShow=showCmd,
                              fMask=shellcon.SEE_MASK_NOCLOSEPROCESS,
                              lpVerb=lpVerb,
                              lpFile=cmd,
                              lpParameters=params)
 
    if wait:
        procHandle = procInfo['hProcess']    
        obj = win32event.WaitForSingleObject(procHandle, win32event.INFINITE)
        rc = win32process.GetExitCodeProcess(procHandle)
        #print "Process handle %s returned code %s" % (procHandle, rc)
    else:
        rc = None
 
    return rc
 
def test():
    rc = 0
    if not isUserAdmin():
        print "You're not an admin.", os.getpid(), "params: ", sys.argv
        #rc = runAsAdmin(["c:\\Windows\\notepad.exe"])
        rc = runAsAdmin()
    else:
        print "You are an admin!", os.getpid(), "params: ", sys.argv
        rc = 0
    x = raw_input('Press Enter to exit.')
    return rc
 
 
if __name__ == "__main__":
    sys.exit(test())

(from this answer, the same accepted answer in How to run script with elevated privilege on windows)

Answer 2

You cannot change privilege at runtime on windows.

An app needs to have a manifest (not suitable for python) or be ran as a privileged user.

When the app starts and privileges are too low, you can ask the user to run as administrator, or let the app relaunch itself with elevated privileges by calling runas.

import ctypes

if not ctypes.windll.shell32.IsUserAnAdmin():
    print('Not enough priviledge, restarting...')
    import sys
    ctypes.windll.shell32.ShellExecuteW(
        None, 'runas', sys.executable, ' '.join(sys.argv), None, None)
else:
    print('Elevated privilege acquired')

Answer 3

The following example builds on Cyrbil's excellent work. In particular, two enumerations are introduced. The first allows for easy specification of how an elevated program is to be opened, and the second helps when errors need to be easily identified. Please note that if you want all command line arguments passed to the new process, sys.argv[0] should probably be replaced with a function call: subprocess.list2cmdline(sys.argv).

#! /usr/bin/env python3
import ctypes
import enum
import sys


# Reference:
# msdn.microsoft.com/en-us/library/windows/desktop/bb762153(v=vs.85).aspx


class SW(enum.IntEnum):

    HIDE = 0
    MAXIMIZE = 3
    MINIMIZE = 6
    RESTORE = 9
    SHOW = 5
    SHOWDEFAULT = 10
    SHOWMAXIMIZED = 3
    SHOWMINIMIZED = 2
    SHOWMINNOACTIVE = 7
    SHOWNA = 8
    SHOWNOACTIVATE = 4
    SHOWNORMAL = 1


class ERROR(enum.IntEnum):

    ZERO = 0
    FILE_NOT_FOUND = 2
    PATH_NOT_FOUND = 3
    BAD_FORMAT = 11
    ACCESS_DENIED = 5
    ASSOC_INCOMPLETE = 27
    DDE_BUSY = 30
    DDE_FAIL = 29
    DDE_TIMEOUT = 28
    DLL_NOT_FOUND = 32
    NO_ASSOC = 31
    OOM = 8
    SHARE = 26


def bootstrap():
    if ctypes.windll.shell32.IsUserAnAdmin():
        main()
    else:
        hinstance = ctypes.windll.shell32.ShellExecuteW(
            None, 'runas', sys.executable, sys.argv[0], None, SW.SHOWNORMAL
        )
        if hinstance <= 32:
            raise RuntimeError(ERROR(hinstance))


def main():
    # Your Code Here
    print(input('Echo: '))


if __name__ == '__main__':
    bootstrap()