UTCTime type

class pyasn1.type.useful.UTCTime(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Creates UTCTime schema or value object.

UTCTime objects are immutable and duck-type Python 2 unicode or Python 3 str. When used in octet-stream context, UTCTime type assumes “iso-8859-1” encoding.

Keyword Arguments:
 
  • value (unicode, str, bytes or UTCTime object) – unicode object (Python 2) or string (Python 3), alternatively string (Python 2) or bytes (Python 3) representing octet-stream of serialised unicode string (note encoding parameter) or UTCTime class instance.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when UTCTime object is used in octet-stream context.
Raises:

PyAsn1Error – On constraint violation or bad initializer.

Note

The UTCTime type models a character string representing date and time.

Formal syntax for the UTCTime value is:

  • YYMMDDhhmm[ss] standing for UTC time, two digits for the year, two for the month, two for the day and two for the hour, followed by two digits for the minutes and two for the seconds if required or
  • a string as above followed by the letter “Z” (denoting a UTC time) or
  • a string as above followed by a string (+|-)hhmm denoting time zone offset relative to UTC

For example, 170126120000Z which stands for YYMMDDHHMMSSZ.

clone(self, value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Create a modified version of UTCTime schema or value object.

The clone() method accepts the same set arguments as UTCTime class takes on instantiation except that all arguments of the clone() method are optional.

Whatever arguments are supplied, they are used to create a copy of self taking precedence over the ones used to instantiate self.

Note

Due to the immutable nature of the UTCTime object, if no arguments are supplied, no new UTCTime object will be created and self will be returned instead.

subtype(self, value=NoValue(), implicitTag=TagSet(), explicitTag=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Create a specialization of UTCTime schema or value object.

The subtype relationship between ASN.1 types has no correlation with subtype relationship between Python types. ASN.1 type is mainly identified by its tag(s) (TagSet) and value range constraints (ConstraintsIntersection). These ASN.1 type properties are implemented as UTCTime attributes.

The subtype() method accepts the same set arguments as UTCTime class takes on instantiation except that all parameters of the subtype() method are optional.

With the exception of the arguments described below, the rest of supplied arguments they are used to create a copy of self taking precedence over the ones used to instantiate self.

The following arguments to subtype() create a ASN.1 subtype out of UTCTime type:

Other Parameters:
 
  • implicitTag (Tag) – Implicitly apply given ASN.1 tag object to self’s TagSet, then use the result as new object’s ASN.1 tag(s).
  • explicitTag (Tag) – Explicitly apply given ASN.1 tag object to self’s TagSet, then use the result as new object’s ASN.1 tag(s).
  • subtypeSpec (ConstraintsIntersection) – Add ASN.1 constraints object to one of the self’s, then use the result as new object’s ASN.1 constraints.
Returns:

new instance of UTCTime schema or value object

Note

Due to the immutable nature of the UTCTime object, if no arguments are supplied, no new UTCTime object will be created and self will be returned instead.

tagSet = <TagSet object at 0x110ad90f0 tags 0:0:23>

Default TagSet object for UTCTime objects

asDateTime

Create datetime.datetime object from a UTCTime object.

Returns:new instance of datetime.datetime object
fromDateTime(dt)

Create UTCTime object from a datetime.datetime object.

Parameters:dt (datetime.datetime object) – The datetime.datetime object to initialize the UTCTime object from
Returns:new instance of UTCTime value
isSameTypeWith(other, matchTags=True, matchConstraints=True)

Examine UTCTime type for equality with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

Python class inheritance relationship is NOT considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is UTCTime type, False otherwise.
isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine UTCTime type for subtype relationship with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

Python class inheritance relationship is NOT considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is a subtype of UTCTime type, False otherwise.
isValue

Indicate that UTCTime object represents ASN.1 value.

If isValue is False then this object represents just ASN.1 schema.

If isValue is True then, in addition to its ASN.1 schema features, this object can also be used like a Python built-in object (e.g. int, str, dict etc.).

Returns:boolFalse if object represents just ASN.1 schema. True if object represents ASN.1 schema and can be used as a normal value.

Note

There is an important distinction between PyASN1 schema and value objects. The PyASN1 schema objects can only participate in ASN.1 schema-related operations (e.g. defining or testing the structure of the data). Most obvious uses of ASN.1 schema is to guide serialisation codecs whilst encoding/decoding serialised ASN.1 contents.

The PyASN1 value objects can additionally participate in many operations involving regular Python objects (e.g. arithmetic, comprehension etc).