The Utilities API¶

class tango.utils.EventCallback(format='{date} {dev_name} {name} {type} {value}', fd=<_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>, max_buf=100)¶

Useful event callback for test purposes

Usage:

>>> dev = tango.DeviceProxy(dev_name)
>>> cb = tango.utils.EventCallback()
>>> id = dev.subscribe_event("state", tango.EventType.CHANGE_EVENT, cb, [])
2011-04-06 15:33:18.910474 sys/tg_test/1 STATE CHANGE [ATTR_VALID] ON

Allowed format keys are:

date (event timestamp)

reception_date (event reception timestamp)

type (event type)

dev_name (device name)

name (attribute name)

value (event value)

New in PyTango 7.1.4

get_events()¶

Returns the list of events received by this callback

Returns: the list of events received by this callback
Return type: sequence<obj>

push_event(evt)¶: Internal usage only

tango.utils.get_enum_labels(enum_cls)¶

Return list of enumeration labels from Enum class.

The list is useful when creating an attribute, for the enum_labels parameter. The enumeration values are checked to ensure they are unique, start at zero, and increment by one.

Parameters: enum_cls (enum.Enum) – the Enum class to be inspected
Returns: List of label strings
Return type: list
Raises: EnumTypeError – in case the given class is invalid

tango.utils.is_pure_str(obj)¶

Tells if the given object is a python string.

In python 2.x this means any subclass of basestring. In python 3.x this means any subclass of str.

Parameters: obj (object) – the object to be inspected
Returns: True is the given obj is a string or False otherwise
Return type: bool

tango.utils.is_seq(obj)¶

Tells if the given object is a python sequence.

It will return True for any collections.Sequence (list, tuple, str, bytes, unicode), bytearray and (if numpy is enabled) numpy.ndarray

Parameters: obj (object) – the object to be inspected
Returns: True is the given obj is a sequence or False otherwise
Return type: bool

tango.utils.is_non_str_seq(obj)¶

Tells if the given object is a python sequence (excluding string sequences).

It will return True for any collections.Sequence (list, tuple (and bytes in python3)), bytearray and (if numpy is enabled) numpy.ndarray

Parameters: obj (object) – the object to be inspected
Returns: True is the given obj is a sequence or False otherwise
Return type: bool

tango.utils.is_integer(obj)¶

Tells if the given object is a python integer.

It will return True for any int, long (in python 2) and (if numpy is enabled) numpy.integer

Parameters: obj (object) – the object to be inspected
Returns: True is the given obj is a python integer or False otherwise
Return type: bool

tango.utils.is_number(obj)¶

Tells if the given object is a python number.

It will return True for any numbers.Number and (if numpy is enabled) numpy.number

Parameters: obj (object) – the object to be inspected
Returns: True is the given obj is a python number or False otherwise
Return type: bool

tango.utils.is_bool(tg_type, inc_array=False)¶

Tells if the given tango type is boolean

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is boolean or False otherwise

Return type

bool

tango.utils.is_scalar_type(tg_type)¶

Tells if the given tango type is a scalar

Parameters: tg_type (tango.CmdArgType) – tango type
Returns: True if the given tango type is a scalar or False otherwise
Return type: bool

tango.utils.is_array_type(tg_type)¶

Tells if the given tango type is an array type

Parameters: tg_type (tango.CmdArgType) – tango type
Returns: True if the given tango type is an array type or False otherwise
Return type: bool

tango.utils.is_numerical_type(tg_type, inc_array=False)¶

Tells if the given tango type is numerical

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is a numerical or False otherwise

Return type

bool

tango.utils.is_int_type(tg_type, inc_array=False)¶

Tells if the given tango type is integer

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is integer or False otherwise

Return type

bool

tango.utils.is_float_type(tg_type, inc_array=False)¶

Tells if the given tango type is float

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is float or False otherwise

Return type

bool

tango.utils.is_bool_type(tg_type, inc_array=False)¶

Tells if the given tango type is boolean

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is boolean or False otherwise

Return type

bool

tango.utils.is_binary_type(tg_type, inc_array=False)¶

Tells if the given tango type is binary

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is binary or False otherwise

Return type

bool

tango.utils.is_str_type(tg_type, inc_array=False)¶

Tells if the given tango type is string

Parameters

tg_type (tango.CmdArgType) – tango type
inc_array (bool) – (optional, default is False) determines if include array in the list of checked types

Returns

True if the given tango type is string or False otherwise

Return type

bool

tango.utils.obj_2_str(obj, tg_type=None)¶

Converts a python object into a string according to the given tango type

Parameters

obj (object) – the object to be converted
tg_type (tango.CmdArgType) – tango type

Returns

a string representation of the given object

Return type

str

tango.utils.seqStr_2_obj(seq, tg_type, tg_format=None)¶

Translates a sequence<str> to a sequence of objects of give type and format

Parameters

seq (sequence<str>) – the sequence
tg_type (tango.CmdArgType) – tango type
tg_format (tango.AttrDataFormat) – (optional, default is None, meaning SCALAR) tango format

Returns

a new sequence

tango.utils.scalar_to_array_type(tg_type)¶

Gives the array tango type corresponding to the given tango scalar type. Example: giving DevLong will return DevVarLongArray.

Parameters: tg_type (tango.CmdArgType) – tango type
Returns: the array tango type for the given scalar tango type
Return type: tango.CmdArgType
Raises: ValueError – in case the given dtype is not a tango scalar type

tango.utils.get_home()¶

Find user’s home directory if possible. Otherwise raise error.

Returns: user’s home directory
Return type: str

New in PyTango 7.1.4

tango.utils.requires_pytango(min_version=None, conflicts=(), software_name='Software')¶

Determines if the required PyTango version for the running software is present. If not an exception is thrown. Example usage:

from tango import requires_pytango

requires_pytango('7.1', conflicts=['8.1.1'], software='MyDS')

Parameters

min_version (None, str, LooseVersion) – minimum PyTango version [default: None, meaning no minimum required]. If a string is given, it must be in the valid version number format (see: LooseVersion)
conflics (seq<str|LooseVersion>) – a sequence of PyTango versions which conflict with the software using it
software_name (str) – software name using tango. Used in the exception message

Raises

Exception – if the required PyTango version is not met

New in PyTango 8.1.4

tango.utils.requires_tango(min_version=None, conflicts=(), software_name='Software')¶

Determines if the required Tango version for the running software is present. If not an exception is thrown. Example usage:

from tango import requires_tango

requires_tango('7.1', conflicts=['8.1.1'], software='MyDS')

Parameters

min_version (None, str, LooseVersion) – minimum Tango version [default: None, meaning no minimum required]. If a string is given, it must be in the valid version number format (see: LooseVersion)
conflics (seq<str|LooseVersion>) – a sequence of Tango versions which conflict with the software using it
software_name (str) – software name using Tango. Used in the exception message

Raises

Exception – if the required Tango version is not met

New in PyTango 8.1.4