ITango is a PyTango CLI based on IPython. It is designed to be used as an IPython profile.

It is available since PyTango 7.1.2 and has been moved to a separate project since PyTango 9.2.0.

You can start ITango by typing on the command line:

$ itango

or the equivalent:

$ ipython --profile=tango

and you should get something like this:



ITango works like a normal python console, but it gives you in addition a nice set of features from IPython like:

  • proper (bash-like) command completion
  • automatic expansion of python variables, functions, types
  • command history (with up/down arrow keys, %hist command)
  • help system ( object? syntax, help(object))
  • persistently store your favorite variables
  • color modes

For a complete list checkout the IPython web page.

Plus an additional set of Tango specific features:

  • automatic import of Tango objects to the console namespace (tango module, DeviceProxy (=Device), Database, Group and AttributeProxy (=Attribute))
  • device name completion
  • attribute name completion
  • automatic tango object member completion
  • list tango devices, classes, servers
  • customized tango error message
  • tango error introspection
  • switch database
  • refresh database
  • list tango devices, classes
  • store favorite tango objects
  • store favorite tango devices
  • tango color modes

Check the Highlights to see how to put these feature to good use :-)


Tab completion

ITango exports many tango specific objects to the console namespace. These include:

  • the tango module itself

    ITango [1]: tango
    Result [1]: <module 'tango' from ...>
  • The DeviceProxy (=Device), AttributeProxy (=Attribute), Database and Group classes

    ITango [1]: De<tab>
    DeprecationWarning            Device       DeviceProxy
    ITango [2]: Device
    Result [2]: <class 'tango._tango.DeviceProxy'>
    ITango [3]: Device("sys/tg_test/1")
    Result [3]: DeviceProxy(sys/tg_test/1)
    ITango [4]: Datab<tab>
    ITango [4]: Database
    ITango [4]: Att<tab>
    Attribute       AttributeError  AttributeProxy
  • The Tango Database object to which the itango session is currently connected

    ITango [1]: db
    Result [1]: Database(homer, 10000)

Device name completion

ITango knows the complete list of device names (including alias) for the current tango database. This means that when you try to create a new Device, by pressing <tab> you can see a context sensitive list of devices.

ITango [1]: test = Device("<tab>
Display all 3654 possibilities? (y or n) n

ITango [1]: test = Device("sys<tab>
sys/access_control/1  sys/database/2        sys/tautest/1         sys/tg_test/1

ITango [2]: test = Device("sys/tg_test/1")

Attribute name completion

ITango can inspect the list of attributes in case the device server for the device where the attribute resides is running.

ITango [1]: short_scalar = Attribute("sys<tab>
sys/access_control/1/  sys/database/2/        sys/tautest/1/         sys/tg_test/1/

ITango [1]: short_scalar = Attribute("sys/tg_test/1/<tab>
sys/tg_test/1/State                sys/tg_test/1/no_value
sys/tg_test/1/Status               sys/tg_test/1/short_image
sys/tg_test/1/ampli                sys/tg_test/1/short_image_ro
sys/tg_test/1/boolean_image        sys/tg_test/1/short_scalar
sys/tg_test/1/boolean_image_ro     sys/tg_test/1/short_scalar_ro
sys/tg_test/1/boolean_scalar       sys/tg_test/1/short_scalar_rww
sys/tg_test/1/boolean_spectrum     sys/tg_test/1/short_scalar_w
sys/tg_test/1/boolean_spectrum_ro  sys/tg_test/1/short_spectrum
sys/tg_test/1/double_image         sys/tg_test/1/short_spectrum_ro
sys/tg_test/1/double_image_ro      sys/tg_test/1/string_image
sys/tg_test/1/double_scalar        sys/tg_test/1/string_image_ro

ITango [1]: short_scalar = Attribute("sys/tg_test/1/short_scalar")

ITango [29]: print
data_format = tango._tango.AttrDataFormat.SCALAR
  dim_x = 1
  dim_y = 0
has_failed = False
is_empty = False
   name = 'short_scalar'
nb_read = 1
nb_written = 1
quality = tango._tango.AttrQuality.ATTR_VALID
r_dimension = AttributeDimension(dim_x = 1, dim_y = 0)
   time = TimeVal(tv_nsec = 0, tv_sec = 1279723723, tv_usec = 905598)
   type = tango._tango.CmdArgType.DevShort
  value = 47
w_dim_x = 1
w_dim_y = 0
w_dimension = AttributeDimension(dim_x = 1, dim_y = 0)
w_value = 0]

Automatic tango object member completion

When you create a new tango object, (ex.: a device), itango is able to find out dynamically which are the members of this device (including tango commands and attributes if the device is currently running)

ITango [1]: test = Device("sys/tg_test/1")

ITango [2]: test.<tab>
Display all 240 possibilities? (y or n)
test.DevVoid                            test.get_access_control
test.Init                               test.get_asynch_replies
test.State                              test.get_attribute_config
test.Status                             test.get_attribute_config_ex
test.SwitchStates                       test.get_attribute_list

ITango [2]: test.short_<tab>
test.short_image        test.short_scalar       test.short_scalar_rww   test.short_spectrum
test.short_image_ro     test.short_scalar_ro    test.short_scalar_w     test.short_spectrum_ro

ITango [2]: test.short_scalar        # old style: test.read_attribute("short_scalar").value
Result [2]: 252

ITango [3]: test.Dev<tab>
test.DevBoolean               test.DevUShort                test.DevVarShortArray
test.DevDouble                test.DevVarCharArray          test.DevVarStringArray
test.DevFloat                 test.DevVarDoubleArray        test.DevVarULongArray
test.DevLong                  test.DevVarDoubleStringArray  test.DevVarUShortArray
test.DevShort                 test.DevVarFloatArray         test.DevVoid
test.DevString                test.DevVarLongArray
test.DevULong                 test.DevVarLongStringArray

ITango [3]: test.DevDouble(56.433)  # old style: test.command_inout("DevDouble").
Result [3]: 56.433

Tango classes as DeviceProxy

ITango exports all known tango classes as python alias to DeviceProxy. This way, if you want to create a device of class which you already know (say, Libera, for example) you can do:

ITango [1]: lib01 = Libera("BO01/DI/BPM-01")

One great advantage is that the tango device name completion is sensitive to the type of device you want to create. This means that if you are in the middle of writing a device name and you press the <tab> key, only devices of the tango class ‘Libera’ will show up as possible completions.

ITango [1]: bpm1 = Libera("<tab>
BO01/DI/BPM-01  BO01/DI/BPM-09  BO02/DI/BPM-06  BO03/DI/BPM-03  BO03/DI/BPM-11  BO04/DI/BPM-08
BO01/DI/BPM-02  BO01/DI/BPM-10  BO02/DI/BPM-07  BO03/DI/BPM-04  BO04/DI/BPM-01  BO04/DI/BPM-09
BO01/DI/BPM-03  BO01/DI/BPM-11  BO02/DI/BPM-08  BO03/DI/BPM-05  BO04/DI/BPM-02  BO04/DI/BPM-10
BO01/DI/BPM-04  BO02/DI/BPM-01  BO02/DI/BPM-09  BO03/DI/BPM-06  BO04/DI/BPM-03  BO04/DI/BPM-11
BO01/DI/BPM-05  BO02/DI/BPM-02  BO02/DI/BPM-10  BO03/DI/BPM-07  BO04/DI/BPM-04
BO01/DI/BPM-06  BO02/DI/BPM-03  BO02/DI/BPM-11  BO03/DI/BPM-08  BO04/DI/BPM-05
BO01/DI/BPM-07  BO02/DI/BPM-04  BO03/DI/BPM-01  BO03/DI/BPM-09  BO04/DI/BPM-06
BO01/DI/BPM-08  BO02/DI/BPM-05  BO03/DI/BPM-02  BO03/DI/BPM-10  BO04/DI/BPM-07

ITango [1]: bpm1 = Libera("BO01<tab>
BO01/DI/BPM-01  BO01/DI/BPM-03  BO01/DI/BPM-05  BO01/DI/BPM-07  BO01/DI/BPM-09  BO01/DI/BPM-11
BO01/DI/BPM-02  BO01/DI/BPM-04  BO01/DI/BPM-06  BO01/DI/BPM-08  BO01/DI/BPM-10

ITango [1]: bpm1 = Libera("BO01/DI/BPM-01")

Customized device representation

When you use ipython >= 0.11 with a Qt console frontend:

$ itango qtconsole

typing a variable containing a tango device object followend by Enter will present you with a customized representation of the object instead of the usual repr() :


You can customize the icon that itango displays for a specific device. The first thing to do is to copy the image file into itango.resource installation directory (if you don’t have permissions to do so, copy the image into a directory of your choosing and make sure it is accessible from itango).

If you want to use the image for all devices of a certain tango class, just add a new tango class property called __icon. You can do it with jive or, of course, with itango itself:

db.put_class_property("Libera", dict(__icon="libera.png"))

# if you placed your image in a directory different than itango.resource
# then, instead you have to specify the absolute directory

db.put_class_property("Libera", dict(__icon="/home/homer/.config/itango/libera.png"))

If you need different images for different devices of the same class, you can specify an __icon property at the device level (which takes precedence over the class property value, if defined):

db.put_device_property("BO01/DI/BPM-01", dict(__icon="libera2.png"))

List tango devices, classes, servers

ITango provides a set of magic functions (ipython lingo) that allow you to check for the list tango devices, classes and servers which are registered in the current database.

ITango [1]: lsdev
                                  Device                     Alias                    Server                Class
---------------------------------------- ------------------------- ------------------------- --------------------
              expchan/BL99_Dummy0DCtrl/1                  BL99_0D1                 Pool/BL99      ZeroDExpChannel
                  simulator/bl98/motor08                                      Simulator/BL98            SimuMotor
              expchan/BL99_Dummy0DCtrl/3                  BL99_0D3                 Pool/BL99      ZeroDExpChannel
              expchan/BL99_Dummy0DCtrl/2                  BL99_0D2                 Pool/BL99      ZeroDExpChannel
              expchan/BL99_Dummy0DCtrl/5                  BL99_0D5                 Pool/BL99      ZeroDExpChannel
              expchan/BL99_Dummy0DCtrl/4                  BL99_0D4                 Pool/BL99      ZeroDExpChannel
              expchan/BL99_Dummy0DCtrl/7                  BL99_0D7                 Pool/BL99      ZeroDExpChannel
              expchan/BL99_Dummy0DCtrl/6                  BL99_0D6                 Pool/BL99      ZeroDExpChannel
                  simulator/bl98/motor01                                      Simulator/BL98            SimuMotor
                  simulator/bl98/motor02                                      Simulator/BL98            SimuMotor
                  simulator/bl98/motor03                                      Simulator/BL98            SimuMotor
   mg/BL99/_mg_macserv_26065_-1320158352                                           Pool/BL99           MotorGroup
                  simulator/bl98/motor05                                      Simulator/BL98            SimuMotor
                  simulator/bl98/motor06                                      Simulator/BL98            SimuMotor
                  simulator/bl98/motor07                                      Simulator/BL98            SimuMotor
                simulator/BL98/motctrl01                                      Simulator/BL98        SimuMotorCtrl
              expchan/BL99_Simu0DCtrl1/1                  BL99_0D8                 Pool/BL99      ZeroDExpChannel
             expchan/BL99_UxTimerCtrl1/1                BL99_Timer                 Pool/BL99         CTExpChannel

ITango [1]: lsdevclass
SimuCoTiCtrl                   TangoAccessControl             ZeroDExpChannel
Door                           Motor                          DataBase
MotorGroup                     IORegister                     SimuMotorCtrl
TangoTest                      MacroServer                    TauTest
SimuMotor                      SimuCounterEx                  MeasurementGroup
Pool                           CTExpChannel

ITango [1]: lsserv
MacroServer/BL99               MacroServer/BL98               Pool/V2
Pool/BL99                      Pool/BL98                      TangoTest/test
Pool/tcoutinho                 Simulator/BL98
TangoAccessControl/1           TauTest/tautest                DataBaseds/2
MacroServer/tcoutinho          Simulator/BL99

Customized tango error message and introspection

ITango intercepts tango exceptions that occur when you do tango operations (ex.: write an attribute with a value outside the allowed limits) and tries to display it in a summarized, user friendly way. If you need more detailed information about the last tango error, you can use the magic command ‘tango_error’.

ITango [1]: test = Device("sys/tg_test/1")

ITango [2]: test.no_value
API_AttrValueNotSet : Read value for attribute no_value has not been updated
For more detailed information type: tango_error

ITango [3]: tango_error
Last tango error:
    desc = 'Read value for attribute no_value has not been updated'
  origin = 'Device_3Impl::read_attributes_no_except'
  reason = 'API_AttrValueNotSet'
severity = tango._tango.ErrSeverity.ERR]
    desc = 'Failed to read_attribute on device sys/tg_test/1, attribute no_value'
  origin = 'DeviceProxy::read_attribute()'
  reason = 'API_AttributeFailed'
severity = tango._tango.ErrSeverity.ERR]]

Switching database

You can switch database simply by executing the ‘switchdb <host> [<port>]’ magic command.

ITango [1]: switchdb

Must give new database name in format <host>[:<port>].
<port> is optional. If not given it defaults to 10000.

switchdb homer:10005
switchdb homer 10005
switchdb homer

ITango [2]: db
Database(homer, 10000)

ITango [3]: switchdb bart       # by default port is 10000

ITango [4]: db
Database(bart, 10000)

ITango [5]: switchdb lisa 10005  # you can use spaces between host and port

ITango [6]: db
Database(lisa, 10005)

ITango [7]: switchdb marge:10005   # or the traditional ':'

ITango [8]: db
Database(marge, 10005)

Refreshing the database

When itango starts up or when the database is switched, a query is made to the tango Database device server which provides all necessary data. This data is stored locally in a itango cache which is used to provide all the nice features. If the Database server is changed in some way (ex: a new device server is registered), the local database cache is not consistent anymore with the tango database. Therefore, itango provides a magic command ‘refreshdb’ that allows you to reread all tango information from the database.

ITango [1]: refreshdb

Storing your favorite tango objects for later usage


This feature is not available if you have installed IPython 0.11!

Since version 7.1.2, DeviceProxy, AttributeProxy and Database became pickable. This means that they can be used by the IPython ‘store’ magic command (type ‘store?’ on the itango console to get information on how to use this command). You can, for example, assign your favorite devices in local python variables and then store these for the next time you startup IPython with itango profile.

ITango [1]: theta = Motor("BL99_M1")  # notice how we used tango alias

ITango [2]: store theta
Stored 'theta' (DeviceProxy)

ITango [3]: Ctrl+D

(IPython session is closed and started again...)

ITango [1]: store -r # in some versions of IPython you may need to do this ...

ITango [1]: print theta

Adding itango to your own ipython profile

Adding itango to the ipython default profile

Let’s assume that you find itango so useful that each time you start ipython, you want itango features to be loaded by default. The way to do this is by editing your default ipython configuration file:

  1. On IPython <= 0.10

    $HOME/.ipython/ and add the lines 1 and 7.


    The code shown below is a small part of your $HOME/.ipython/ It is shown here only the relevant part for this example.

    import itango
    def main():
        # uncomment if you want to get ipython -p sh behaviour
        # without having to use command line switches
        # import ipy_profile_sh
        itango.init_ipython(ip, console=False)
  2. On IPython > 0.10

    First you have to check which is the configuration directory being used by IPython. For this, in an IPython console type:

    ITango [1]: import IPython.utils.path
    ITango [2]: IPython.utils.path.get_ipython_dir()

    now edit <IPYTHON_DIR>/profile_default/ and add the following line at the end to add itango configuration:

    load_subconfig('', profile='tango')

    Alternatively, you could also load itango as an IPython extension:

    config = get_config()
    i_shell_app = config.InteractiveShellApp
    extensions = getattr(i_shell_app, 'extensions', [])
    i_shell_app.extensions = extensions

    for more information on how to configure IPython >= 0.11 please check the IPython configuration

And now, every time you start ipython:


itango features will also be loaded.

In [1]: db
Out[1]: Database(homer, 10000)

Adding itango to an existing customized profile


This chapter has a pending update. The contents only apply to IPython <= 0.10.

If you have been working with IPython before and have already defined a customized personal profile, you can extend your profile with itango features without breaking your existing options. The trick is to initialize itango extension with a parameter that tells itango to maintain the existing options (like colors, command line and initial banner).

So, for example, let’s say you have created a profile called nuclear, and therefore you have a file called $HOME/.ipython/ with the following contents:

import os
import IPython.ipapi

def main():
    ip = IPython.ipapi.get()

    o = ip.options
    o.banner = "Springfield nuclear powerplant CLI\n\nWelcome Homer Simpson"
    o.colors = "Linux"
    o.prompt_in1 = "Mr. Burns owns you [\\#]: "


In order to have itango features available to this profile you simply need to add two lines of code (lines 3 and 7):

import os
import IPython.ipapi
import itango

def main():
    ip = IPython.ipapi.get()
    itango.init_ipython(ip, console=False)

    o = ip.options
    o.banner = "Springfield nuclear powerplant CLI\n\nMr. Burns owns you!"
    o.colors = "Linux"
    o.prompt_in1 = "The Simpsons [\\#]: "


This will load the itango features into your profile while preserving your profile’s console options (like colors, command line and initial banner).

Creating a profile that extends itango profile


This chapter has a pending update. The contents only apply to IPython <= 0.10.

It is also possible to create a profile that includes all itango features and at the same time adds new ones. Let’s suppose that you want to create a customized profile called ‘orbit’ that automatically exports devices of class ‘Libera’ for the booster accelerator (assuming you are working on a synchrotron like institute ;-). Here is the code for the $HOME/.ipython/

import os
import IPython.ipapi
import IPython.genutils
import IPython.ColorANSI
import itango
import StringIO

def magic_liberas(ip, p=''):
    """Lists all known Libera devices."""
    data = itango.get_device_map()
    s = StringIO.StringIO()
    cols = 30, 15, 20
    l = "%{0}s %{1}s %{2}s".format(*cols)
    print >>s, l % ("Device", "Alias", "Server")
    print >>s, l % (cols[0]*"-", cols[1]*"-", cols[2]*"-")
    for d, v in data.items():
        if v[2] != 'Libera': continue
        print >>s, l % (d, v[0], v[1])

def main():
    ip = IPython.ipapi.get()


    o = ip.options

    Colors = IPython.ColorANSI.TermColors
    c = dict(Colors.__dict__)

    o.banner += "\n{Brown}Welcome to Orbit analysis{Normal}\n".format(**c)

    o.prompt_in1 = "Orbit [\\#]: "
    o.colors = "BlueTango"

    ip.expose_magic("liberas", magic_liberas)

    db = ip.user_ns.get('db')
    dev_class_dict = itango.get_class_map()

    if not dev_class_dict.has_key("Libera"):

    for libera in dev_class_dict['Libera']:
        domain, family, member = libera.split("/")
        var_name = domain + "_" + member
        var_name = var_name.replace("-","_")
        ip.to_user_ns( { var_name : tango.DeviceProxy(libera) } )


Then start your CLI with:

$ ipython --profile=orbit

and you will have something like this


Advanced event monitoring

With itango it is possible to monitor change events triggered by any tango attribute which has events enabled.

To start monitoring the change events of an attribute:

ITango [1]: mon -a BL99_M1/Position
'BL99_M1/Position' is now being monitored. Type 'mon' to see all events

To list all events that have been intercepted:

ITango [2]: mon
  ID           Device    Attribute            Value       Quality             Time
---- ---------------- ------------ ---------------- ------------- ----------------
   0     motor/bl99/1        state               ON    ATTR_VALID  17:11:08.026472
   1     motor/bl99/1     position            190.0    ATTR_VALID  17:11:20.691112
   2     motor/bl99/1        state           MOVING    ATTR_VALID  17:12:11.858985
   3     motor/bl99/1     position    188.954072857 ATTR_CHANGING  17:12:11.987817
   4     motor/bl99/1     position    186.045533882 ATTR_CHANGING  17:12:12.124448
   5     motor/bl99/1     position    181.295838155 ATTR_CHANGING  17:12:12.260884
   6     motor/bl99/1     position     174.55354729 ATTR_CHANGING  17:12:12.400036
   7     motor/bl99/1     position     166.08870515 ATTR_CHANGING  17:12:12.536387
   8     motor/bl99/1     position     155.77528943 ATTR_CHANGING  17:12:12.672846
   9     motor/bl99/1     position    143.358230136 ATTR_CHANGING  17:12:12.811878
  10     motor/bl99/1     position    131.476140017 ATTR_CHANGING  17:12:12.950391
  11     motor/bl99/1     position    121.555421781 ATTR_CHANGING  17:12:13.087970
  12     motor/bl99/1     position    113.457930987 ATTR_CHANGING  17:12:13.226531
  13     motor/bl99/1     position    107.319423091 ATTR_CHANGING  17:12:13.363559
  14     motor/bl99/1     position    102.928229946 ATTR_CHANGING  17:12:13.505102
  15     motor/bl99/1     position    100.584726495 ATTR_CHANGING  17:12:13.640794
  16     motor/bl99/1     position            100.0    ATTR_ALARM  17:12:13.738136
  17     motor/bl99/1        state            ALARM    ATTR_VALID  17:12:13.743481

ITango [3]: mon -l mot.* state
  ID           Device    Attribute            Value       Quality             Time
---- ---------------- ------------ ---------------- ------------- ----------------
   0     motor/bl99/1        state               ON    ATTR_VALID  17:11:08.026472
   2     motor/bl99/1        state           MOVING    ATTR_VALID  17:12:11.858985
  17     motor/bl99/1        state            ALARM    ATTR_VALID  17:12:13.743481

To stop monitoring the attribute:

ITango [1]: mon -d BL99_M1/Position
Stopped monitoring 'BL99_M1/Position'


Type ‘mon?’ to see detailed information about this magic command