Group

Group class

class tango.Group(name)

Bases: object

A Tango Group represents a hierarchy of tango devices. The hierarchy may have more than one level. The main goal is to group devices with same attribute(s)/command(s) to be able to do parallel requests.

add(self, subgroup, timeout_ms=-1) → None

Attaches a (sub)_RealGroup.

To remove the subgroup use the remove() method.

Parameters:

subgroup:

(str)

timeout_ms:

(int) If timeout_ms parameter is different from -1, the client side timeout associated to each device composing the _RealGroup added is set to timeout_ms milliseconds. If timeout_ms is -1, timeouts are not changed.

Return:

None

Throws:

TypeError, ArgumentError

command_inout(self, cmd_name, forward=True) → sequence<GroupCmdReply>

command_inout(self, cmd_name, param, forward=True) → sequence<GroupCmdReply>

command_inout(self, cmd_name, param_list, forward=True) → sequence<GroupCmdReply>

Just a shortcut to do:

self.command_inout_reply(self.command_inout_asynch(…))

Parameters:

cmd_name:

(str) Command name

param:

(any) parameter value

param_list:

(tango.DeviceDataList) sequence of parameters. When given, it’s length must match the group size.

forward:

(bool) If it is set to true (the default) request is forwarded to subgroups. Otherwise, it is only applied to the local set of devices.

Return:

(sequence<GroupCmdReply>)

command_inout_reply(self, req_id, timeout_ms=0) → sequence<GroupCmdReply>

Returns the results of an asynchronous command.

Parameters:

req_id:

(int) Is a request identifier previously returned by one of the command_inout_asynch methods

timeout_ms:

(int) For each device in the hierarchy, if the command result is not yet available, command_inout_reply wait timeout_ms milliseconds before throwing an exception. This exception will be part of the global reply. If timeout_ms is set to 0, command_inout_reply waits “indefinitely”.

Return:

(sequence<GroupCmdReply>)

Throws:

contains(self, pattern, forward=True) → bool

Parameters:

pattern:

(str) The pattern can be a fully qualified or simple group name, a device name or a device name pattern.

forward:

(bool) If fwd is set to true (the default), the remove request is also forwarded to subgroups. Otherwise, it is only applied to the local set of elements.

Return:

(bool) Returns true if the hierarchy contains groups and/or devices which name matches the specified pattern. Returns false otherwise.

Throws:

disable(*args, **kwds)

Disables a group or a device element in a group.

enable(*args, **kwds)

Enables a group or a device element in a group.

get_device_list(self, forward=True) → sequence<str>

Considering the following hierarchy:

g2.add("my/device/04")
g2.add("my/device/05")

g4.add("my/device/08")
g4.add("my/device/09")

g3.add("my/device/06")
g3.add(g4)
g3.add("my/device/07")

g1.add("my/device/01")
g1.add(g2)
g1.add("my/device/03")
g1.add(g3)
g1.add("my/device/02")

The returned vector content depends on the value of the forward option. If set to true, the results will be organized as follows:

    dl = g1.get_device_list(True)

dl[0] contains "my/device/01" which belongs to g1
dl[1] contains "my/device/04" which belongs to g1.g2
dl[2] contains "my/device/05" which belongs to g1.g2
dl[3] contains "my/device/03" which belongs to g1
dl[4] contains "my/device/06" which belongs to g1.g3
dl[5] contains "my/device/08" which belongs to g1.g3.g4
dl[6] contains "my/device/09" which belongs to g1.g3.g4
dl[7] contains "my/device/07" which belongs to g1.g3
dl[8] contains "my/device/02" which belongs to g1

If the forward option is set to false, the results are:

    dl = g1.get_device_list(False);

dl[0] contains "my/device/01" which belongs to g1
dl[1] contains "my/device/03" which belongs to g1
dl[2] contains "my/device/02" which belongs to g1

Parameters:

forward:

(bool) If it is set to true (the default), the request is forwarded to sub-groups. Otherwise, it is only applied to the local set of devices.

Return:

(sequence<str>) The list of devices currently in the hierarchy.

Throws:

get_fully_qualified_name(*args, **kwds)

Get the complete (dpt-separated) name of the group. This takes into consideration the name of the group and its parents.

get_name(*args, **kwds)

Get the name of the group. Eg: Group(‘name’).get_name() == ‘name’

get_size(self, forward=True) → int

Parameters:

forward:

(bool) If it is set to true (the default), the request is forwarded to sub-groups.

Return:

(int) The number of the devices in the hierarchy

Throws:

is_enabled(*args, **kwds)

Check if a group is enabled. New in PyTango 7.0.0

name_equals(*args, **kwds)

New in PyTango 7.0.0

name_matches(*args, **kwds)

New in PyTango 7.0.0

ping(self, forward=True) → bool

Ping all devices in a group.

Parameters:

forward:

(bool) If fwd is set to true (the default), the request is also forwarded to subgroups. Otherwise, it is only applied to the local set of devices.

Return:

(bool) This method returns true if all devices in the group are alive, false otherwise.

Throws:

read_attribute(self, attr_name, forward=True) → sequence<GroupAttrReply>

Just a shortcut to do:

self.read_attribute_reply(self.read_attribute_asynch(…))

read_attribute_asynch(self, attr_name, forward=True, reserved=-1) → int

Reads an attribute on each device in the group asynchronously. The method sends the request to all devices and returns immediately.

Parameters:

attr_name:

(str) Name of the attribute to read.

forward:

(bool) If it is set to true (the default) request is forwarded to subgroups. Otherwise, it is only applied to the local set of devices.

reserved:

(int) is reserved for internal purpose and should not be used. This parameter may disappear in a near future.

Return:

(int) request id. Pass the returned request id to Group.read_attribute_reply() to obtain the results.

Throws:

read_attribute_reply(self, req_id, timeout_ms=0) → sequence<GroupAttrReply>

Returns the results of an asynchronous attribute reading.

Parameters:

req_id:

(int) a request identifier previously returned by read_attribute_asynch.

timeout_ms:

(int) For each device in the hierarchy, if the attribute value is not yet available, read_attribute_reply wait timeout_ms milliseconds before throwing an exception. This exception will be part of the global reply. If timeout_ms is set to 0, read_attribute_reply waits “indefinitely”.

Return:

(sequence<GroupAttrReply>)

Throws:

read_attributes(self, attr_names, forward=True) → sequence<GroupAttrReply>

Just a shortcut to do:

self.read_attributes_reply(self.read_attributes_asynch(…))

read_attributes_asynch(self, attr_names, forward=True, reserved=-1) → int

Reads the attributes on each device in the group asynchronously. The method sends the request to all devices and returns immediately.

Parameters:

attr_names:

(sequence<str>) Name of the attributes to read.

forward:

(bool) If it is set to true (the default) request is forwarded to subgroups. Otherwise, it is only applied to the local set of devices.

reserved:

(int) is reserved for internal purpose and should not be used. This parameter may disappear in a near future.

Return:

(int) request id. Pass the returned request id to Group.read_attributes_reply() to obtain the results.

Throws:

read_attributes_reply(self, req_id, timeout_ms=0) → sequence<GroupAttrReply>

Returns the results of an asynchronous attribute reading.

Parameters:

req_id:

(int) a request identifier previously returned by read_attribute_asynch.

timeout_ms:

(int) For each device in the hierarchy, if the attribute value is not yet available, read_attribute_reply ait timeout_ms milliseconds before throwing an exception. This exception will be part of the global reply. If timeout_ms is set to 0, read_attributes_reply waits “indefinitely”.

Return:

(sequence<GroupAttrReply>)

Throws:

remove_all(self) → None

Removes all elements in the _RealGroup. After such a call, the _RealGroup is empty.

set_timeout_millis(self, timeout_ms) → bool

Set client side timeout for all devices composing the group in milliseconds. Any method which takes longer than this time to execute will throw an exception.

Parameters:

timeout_ms:

(int)

Return:

None

Throws:

(errors are ignored)

New in PyTango 7.0.0

write_attribute(self, attr_name, value, forward=True, multi=False) → sequence<GroupReply>

Just a shortcut to do:

self.write_attribute_reply(self.write_attribute_asynch(…))

write_attribute_asynch(self, attr_name, value, forward=True, multi=False) → int

Writes an attribute on each device in the group asynchronously. The method sends the request to all devices and returns immediately.

Parameters:

attr_name:

(str) Name of the attribute to write.

value:

(any) Value to write. See DeviceProxy.write_attribute

forward:

(bool) If it is set to true (the default) request is forwarded to subgroups. Otherwise, it is only applied to the local set of devices.

multi:

(bool) If it is set to false (the default), the same value is applied to all devices in the group. Otherwise the value is interpreted as a sequence of values, and each value is applied to the corresponding device in the group. In this case len(value) must be equal to group.get_size()!

Return:

(int) request id. Pass the returned request id to Group.write_attribute_reply() to obtain the acknowledgements.

Throws:

write_attribute_reply(self, req_id, timeout_ms=0) → sequence<GroupReply>

Returns the acknowledgements of an asynchronous attribute writing.

Parameters:

req_id:

(int) a request identifier previously returned by write_attribute_asynch.

timeout_ms:

(int) For each device in the hierarchy, if the acknowledgment is not yet available, write_attribute_reply wait timeout_ms milliseconds before throwing an exception. This exception will be part of the global reply. If timeout_ms is set to 0, write_attribute_reply waits “indefinitely”.

Return:

(sequence<GroupReply>)

Throws:

GroupReply classes

Group member functions do not return the same as their DeviceProxy counterparts, but objects that contain them. This is:

• write attribute family returns tango.GroupReplyList

• read attribute family returns tango.GroupAttrReplyList

• command inout family returns tango.GroupCmdReplyList

The Group*ReplyList objects are just list-like objects containing GroupReply, GroupAttrReply and GroupCmdReply elements that will be described now.

Note also that GroupReply is the base of GroupCmdReply and GroupAttrReply.

class tango.GroupReply(*args, **kwargs)

This is the base class for the result of an operation on a PyTangoGroup, being it a write attribute, read attribute, or command inout operation.

It has some trivial common operations:

• has_failed(self) -> bool

• group_element_enabled(self) ->bool

• dev_name(self) -> str

• obj_name(self) -> str

• get_err_stack(self) -> DevErrorList

class tango.GroupAttrReply(*args, **kwargs)

Bases:

get_data(self, extract_as=ExtractAs.Numpy) → DeviceAttribute

Get the DeviceAttribute.

Parameters:

extract_as:

(ExtractAs)

Return:

(DeviceAttribute) Whatever is stored there, or None.

class tango.GroupCmdReply(*args, **kwargs)

Bases:

get_data(self) → any

Get the actual value stored in the GroupCmdRply, the command output value. It’s the same as self.get_data_raw().extract()

Parameters:

None

Return:

(any) Whatever is stored there, or None.

get_data_raw(self) → any

Get the DeviceData containing the output parameter of the command.

Parameters:

None

Return:

(DeviceData) Whatever is stored there, or None.