how to use os.environ as a dictionary value

Question

Having some issues creating a dictionzry which should contain an env variable as a value per key. It's the single quotes that are causing the problem I guess. Could someone point me to a pythonic way of doing this ? :)

macros = {
   'date': os.environ['NOTIFY_SHORTDATETIME'],
   'hostname': os.environ['NOTIFY_HOSTNAME'],
   'ip': os.environ['NOTIFY_HOSTADDRESS'],
   'alias': os.environ['NOTIFY_HOSTALIAS'],
   'hostcmd': os.environ['NOTIFY_HOSTCHECKCOMMAND'],
   'servicecmd': os.environ['NOTIFY_SERVICECHECKCOMMAND'],
   'servicenotifnum': os.environ['NOTIFY_SERVICENOTIFICATIONNUMBER'],
   'servicedesc': os.environ['NOTIFY_SERVICEDESC'],
   'hostoutput': os.environ['NOTIFY_HOSTOUTPUT'],
   'serviceoutput': os.environ['NOTIFY_SERVICEOUTPUT'],
   'hoststate': os.environ['NOTIFY_HOSTSTATE'],
   'svcstate': os.environ['NOTIFY_SERVICESTATE'],
   'lasthoststate': os.environ['NOTIFY_LASTHOSTSTATE'],
   'laststatesvc': os.environ['NOTIFY_LASTSTATESERVICE'],
   'notiftype': os.environ['NOTIFY_NOTIFICATIONTYPE'],
}

Answer 1

Key Error means that the named item does not exist in the os.environ . If you are trying to find out what does exist on your machine, you can debug and print out the list like:

import os
for k in os.environ:
  print k

On my Windows XP box, I get these output:

TMP
COMPUTERNAME
USERDOMAIN
PSMODULEPATH
COMMONPROGRAMFILES
PROCESSOR_IDENTIFIER
PROGRAMFILES
PROCESSOR_REVISION
SYSTEMROOT
PATH
PROGRAMFILES(X86)
COMSPEC
TEMP
COMMONPROGRAMFILES(X86
PROCESSOR_ARCHITECTURE
ALLUSERSPROFILE
LOCALAPPDATA
HOMEPATH
UATDATA
VS120COMNTOOLS
PROGRAMW6432
USERNAME
LOGONSERVER
PROMPT
SESSIONNAME
PROGRAMDATA
USERDNSDOMAIN
PATHEXT
FP_NO_HOST_CHECK
WINDIR
APPDATA
HOMEDRIVE
SYSTEMDRIVE
NUMBER_OF_PROCESSORS
VBOX_INSTALL_PATH
PROCESSOR_LEVEL
PROCESSOR_ARCHITEW6432
COMMONPROGRAMW6432
OS
PUBLIC
USERPROFILE

Based on the error you're getting, it seems that you're trying to use environment variables for a different operating system than whatever you're actually using. You should resolve this by referring to the correct OS environment variables for your computer.

Answer 2

You can wrap os.environ with dict()

Python3 example:

In [1]: import os

In [2]: os.environ.clear()

In [3]: os.environ
Out[3]: environ{}

In [4]: os.environ['FOO']='bar'

In [5]: os.environ
Out[5]: environ{'FOO': 'bar'}

In [6]: type(os.environ)
Out[6]: os._Environ

In [7]: type(dict(os.environ))
Out[7]: dict

In [8]: foo = dict(os.environ)

In [9]: foo['FOO']
Out[9]: 'bar'