icalendar.cal.available module#
This implements the sub-component "AVAILABLE" of "VAVAILABILITY".
This is specified in RFC 7953.
- class icalendar.cal.available.Available(*args, **kwargs)[source]#
Bases:
ComponentSub-component of "VAVAILABILITY from RFC 7953.
- Description:
"AVAILABLE" subcomponents are used to indicate periods of free time within the time range of the enclosing "VAVAILABILITY" component. "AVAILABLE" subcomponents MAY include recurrence properties to specify recurring periods of time, which can be overridden using normal iCalendar recurrence behavior (i.e., use of the "RECURRENCE-ID" property).
Examples
This is a recurring "AVAILABLE" subcomponent:
BEGIN:AVAILABLE UID:57DD4AAF-3835-46B5-8A39-B3B253157F01 SUMMARY:Monday to Friday from 9:00 to 17:00 DTSTART;TZID=America/Denver:20111023T090000 DTEND;TZID=America/Denver:20111023T170000 RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR LOCATION:Denver END:AVAILABLE
You can get the same example from
example():Set keys to upper for initial dict.
- property CREATED: datetime | None#
The CREATED property. datetime in UTC
All values will be converted to a datetime in UTC.
CREATED specifies the date and time that the calendar information was created by the calendar user agent in the calendar store.
- Conformance:
The property can be specified once in "VEVENT", "VTODO", or "VJOURNAL" calendar components. The value MUST be specified as a date with UTC time.
- property DTEND: datetime | None#
The DTEND property. datetime in UTC
All values will be converted to a datetime in UTC. Start of the component.
This is almost the same as
Event.DTENDwith one exception: The values MUST have a timezone and DATE is not allowed.- Description:
RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.
- property DTSTAMP: datetime | None#
The DTSTAMP property. datetime in UTC
All values will be converted to a datetime in UTC. RFC 5545:
Conformance: This property MUST be included in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components.
Description: In the case of an iCalendar object that specifies a "METHOD" property, this property specifies the date and time that the instance of the iCalendar object was created. In the case of an iCalendar object that doesn't specify a "METHOD" property, this property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.
The value MUST be specified in the UTC time format.
In the case of an iCalendar object that doesn't specify a "METHOD" property, this property is equivalent to the "LAST-MODIFIED" property.
- property DTSTART: datetime | None#
The DTSTART property. datetime in UTC
All values will be converted to a datetime in UTC. Start of the component.
This is almost the same as
Event.DTSTARTwith one exception: The values MUST have a timezone and DATE is not allowed.- Description:
RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.
- property DURATION: timedelta | None#
The DURATION property.
The "DTSTART" property for a "Available" specifies the inclusive start of the Available. The "DURATION" property in conjunction with the DTSTART property for a "Available" calendar component specifies the non-inclusive end of the event.
If you would like to calculate the duration of a Available, do not use this. Instead use the duration property (lower case).
- property LAST_MODIFIED: datetime | None#
The LAST-MODIFIED property. datetime in UTC
All values will be converted to a datetime in UTC. RFC 5545:
Purpose: This property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.
Note: This is analogous to the modification date and time for a file in the file system.
Conformance: This property can be specified in the "VEVENT", "VTODO", "VJOURNAL", or "VTIMEZONE" calendar components.
- add(name, value, parameters=None, encode=True)#
Add a property.
- Parameters:
name (string) – Name of the property.
value (Python native type or icalendar property type.) – Value of the property. Either of a basic Python type of any of the icalendar's own property types.
parameters (Dictionary) – Property parameter dictionary for the value. Only available, if encode is set to True.
encode (Boolean) – True, if the value should be encoded to one of icalendar's own property types (Fallback is "vText") or False, if not.
- Returns:
None
- add_component(component)#
Add a subcomponent to this component.
- property categories: list[str]#
This property defines the categories for a component.
- Property Parameters:
IANA, non-standard, and language property parameters can be specified on this property.
- Conformance:
The property can be specified within "VEVENT", "VTODO", or "VJOURNAL" calendar components. Since RFC 7986 it can also be defined on a "VCALENDAR" component.
- Description:
This property is used to specify categories or subtypes of the calendar component. The categories are useful in searching for a calendar component of a particular type and category. Within the "VEVENT", "VTODO", or "VJOURNAL" calendar components, more than one category can be specified as a COMMA-separated list of categories.
Example
Below, we add the categories to an event:
>>> from icalendar import Event >>> event = Event() >>> event.categories = ["Work", "Meeting"] >>> print(event.to_ical()) BEGIN:VEVENT CATEGORIES:Work,Meeting END:VEVENT >>> event.categories.append("Lecture") >>> event.categories == ["Work", "Meeting", "Lecture"] True
Note
At present, we do not take the LANGUAGE parameter into account.
See also
Component.concepts
- clear()#
Remove all items from ordered dict.
- property comments: list[str]#
COMMENT is used to specify a comment to the calendar user.
- Purpose:
This property specifies non-processing information intended to provide a comment to the calendar user.
- Conformance:
In RFC 5545, this property can be specified multiple times in "VEVENT", "VTODO", "VJOURNAL", and "VFREEBUSY" calendar components as well as in the "STANDARD" and "DAYLIGHT" sub-components. In RFC 7953, this property can be specified multiple times in "VAVAILABILITY" and "VAVAILABLE".
- Property Parameters:
IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.
- property concepts: list[vUri]#
CONCEPT
- Purpose:
CONCEPT defines the formal categories for a calendar component.
- Conformance:
Since RFC 9253, this property can be specified zero or more times in any iCalendar component.
- Description:
This property is used to specify formal categories or classifications of the calendar component. The values are useful in searching for a calendar component of a particular type and category.
This categorization is distinct from the more informal "tagging" of components provided by the existing CATEGORIES property. It is expected that the value of the CONCEPT property will reference an external resource that provides information about the categorization.
In addition, a structured URI value allows for hierarchical categorization of events.
Possible category resources are the various proprietary systems, for example, the Library of Congress, or an open source of categorization data.
Examples
The following is an example of this property. It points to a server acting as the source for the calendar object.
CONCEPT:https://example.com/event-types/arts/music
See also
Component.categories
- property contacts: list[str]#
Contact information associated with the calendar component.
- Purpose:
This property is used to represent contact information or alternately a reference to contact information associated with the calendar component.
- Property Parameters:
IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.
- Conformance:
In RFC 5545, this property can be specified in a "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar component. In RFC 7953, this property can be specified in a "VAVAILABILITY" amd "VAVAILABLE" calendar component.
- Description:
The property value consists of textual contact information. An alternative representation for the property value can also be specified that refers to a URI pointing to an alternate form, such as a vCard RFC 2426, for the contact information.
Example
The following is an example of this property referencing textual contact information:
CONTACT:Jim Dolittle\, ABC Industries\, +1-919-555-1234
The following is an example of this property with an alternate representation of an LDAP URI to a directory entry containing the contact information:
CONTACT;ALTREP="ldap://example.com:6666/o=ABC%20Industries\, c=US???(cn=Jim%20Dolittle)":Jim Dolittle\, ABC Industries\, +1-919-555-1234
The following is an example of this property with an alternate representation of a MIME body part containing the contact information, such as a vCard RFC 2426 embedded in a text/ directory media type RFC 2425:
CONTACT;ALTREP="CID:part3.msg970930T083000SILVER@example.com": Jim Dolittle\, ABC Industries\, +1-919-555-1234
The following is an example of this property referencing a network resource, such as a vCard RFC 2426 object containing the contact information:
CONTACT;ALTREP="http://example.com/pdi/jdoe.vcf":Jim Dolittle\, ABC Industries\, +1-919-555-1234
- content_line(name, value, sorted=True)#
Returns property as content line.
- content_lines(sorted=True)#
Converts the Component and subcomponents into content lines.
- copy(recursive=False)#
Copy the component.
- Parameters:
recursive (
bool) – IfTrue, this creates copies of the component, its subcomponents, and all its properties. IfFalse, this only creates a shallow copy of the component.- Return type:
- Returns:
A copy of the component.
Examples
Create a shallow copy of a component:
>>> from icalendar import Event >>> event = Event.new(description="Event to be copied") >>> event_copy = event.copy() >>> str(event_copy.description) 'Event to be copied'
Shallow copies lose their subcomponents:
>>> from icalendar import Calendar >>> calendar = Calendar.example() >>> len(calendar.subcomponents) 3 >>> calendar_copy = calendar.copy() >>> len(calendar_copy.subcomponents) 0
A recursive copy also copies all the subcomponents:
>>> full_calendar_copy = calendar.copy(recursive=True) >>> len(full_calendar_copy.subcomponents) 3 >>> full_calendar_copy.events[0] == calendar.events[0] True >>> full_calendar_copy.events[0] is calendar.events[0] False
- property created: datetime#
Datetime when the information associated with the component was created.
Since
CREATEDis an optional property, this returnsDTSTAMPifCREATEDis not set.
- decoded(name, default=[])#
Returns decoded value of property.
A component maps keys to icalendar property value types. This function returns values compatible to native Python types.
- Return type:
- property description: str | None#
DESCRIPTION provides a more complete description of the calendar component than that provided by the "SUMMARY" property.
- Property Parameters:
IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.
- Conformance:
The property can be specified in the "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar components. The property can be specified multiple times only within a "VJOURNAL" calendar component.
- Description:
This property is used in the "VEVENT" and "VTODO" to capture lengthy textual descriptions associated with the activity.
This property is used in the "VALARM" calendar component to capture the display text for a DISPLAY category of alarm, and to capture the body text for an EMAIL category of alarm.
Examples
The following is an example of this property with formatted line breaks in the property value:
DESCRIPTION:Meeting to provide technical review for "Phoenix" design.\nHappy Face Conference Room. Phoenix design team MUST attend this meeting.\nRSVP to team leader.
- property duration: timedelta | None#
Compute the duration of this component.
If there is no
DTENDorDURATIONset, this is None. Otherwise, the duration is calculated fromDTSTARTandDTEND/DURATION.This is in accordance with RFC 7953: If "DTEND" or "DURATION" are not present, then the end time is unbounded.
- property end: timedelta | None#
Compute the duration of this component.
If there is no
DTENDorDURATIONset, this is None. Otherwise, the duration is calculated fromDTSTARTandDTEND/DURATION.This is in accordance with RFC 7953: If "DTEND" or "DURATION" are not present, then the end time is unbounded.
- classmethod example(name='rfc_7953_1')[source]#
Return the calendar example with the given name.
- Return type:
- property exdates: list[date | datetime]#
EXDATE defines the list of DATE-TIME exceptions for recurring components.
EXDATE is defined in RFC 5545.
- Value Type:
The default value type for this property is DATE-TIME. The value type can be set to DATE.
- Property Parameters:
IANA, non-standard, value data type, and time zone identifier property parameters can be specified on this property.
- Conformance:
This property can be specified in recurring "VEVENT", "VTODO", and "VJOURNAL" calendar components as well as in the "STANDARD" and "DAYLIGHT" sub-components of the "VTIMEZONE" calendar component.
- Description:
The exception dates, if specified, are used in computing the recurrence set. The recurrence set is the complete set of recurrence instances for a calendar component. The recurrence set is generated by considering the initial "DTSTART" property along with the "RRULE", "RDATE", and "EXDATE" properties contained within the recurring component. The "DTSTART" property defines the first instance in the recurrence set. The "DTSTART" property value SHOULD match the pattern of the recurrence rule, if specified. The recurrence set generated with a "DTSTART" property value that doesn't match the pattern of the rule is undefined. The final recurrence set is generated by gathering all of the start DATE-TIME values generated by any of the specified "RRULE" and "RDATE" properties, and then excluding any start DATE-TIME values specified by "EXDATE" properties. This implies that start DATE-TIME values specified by "EXDATE" properties take precedence over those specified by inclusion properties (i.e., "RDATE" and "RRULE"). When duplicate instances are generated by the "RRULE" and "RDATE" properties, only one recurrence is considered. Duplicate instances are ignored.
The "EXDATE" property can be used to exclude the value specified in "DTSTART". However, in such cases, the original "DTSTART" date MUST still be maintained by the calendaring and scheduling system because the original "DTSTART" value has inherent usage dependencies by other properties such as the "RECURRENCE-ID".
Example
Below, we add an exdate in a list and get the resulting list of exdates.
>>> from icalendar import Event >>> from datetime import datetime >>> event = Event() # Add a list of excluded dates >>> event.add("EXDATE", [datetime(2025, 4, 28, 16, 5)]) >>> event.exdates [datetime.datetime(2025, 4, 28, 16, 5)]
Note
You cannot modify the EXDATE value by modifying the result. Use
icalendar.cal.Component.add()to add values.If you want to compute recurrences, have a look at Related Projects.
- classmethod from_ical(st, multiple=False)#
Parse iCalendar data into component instances.
Handles standard and custom components (
X-*, IANA-registered).- Parameters:
- Return type:
- Returns:
Component or list of components
See also
Custom components for examples of parsing custom components
- classmethod from_jcal(jcal)#
Create a component from a jCal list.
- Parameters:
jcal (
str|list) – jCal list or JSON string according to RFC 7265.- Raises:
JCalParsingError – If the jCal provided is invalid.
JSONDecodeError – If the provided string is not valid JSON.
- Return type:
This reverses
to_json()andto_jcal().The following code parses an example from RFC 7265:
>>> from icalendar import Component >>> jcal = ["vcalendar", ... [ ... ["calscale", {}, "text", "GREGORIAN"], ... ["prodid", {}, "text", "-//Example Inc.//Example Calendar//EN"], ... ["version", {}, "text", "2.0"] ... ], ... [ ... ["vevent", ... [ ... ["dtstamp", {}, "date-time", "2008-02-05T19:12:24Z"], ... ["dtstart", {}, "date", "2008-10-06"], ... ["summary", {}, "text", "Planning meeting"], ... ["uid", {}, "text", "4088E990AD89CB3DBB484909"] ... ], ... [] ... ] ... ] ... ] >>> calendar = Component.from_jcal(jcal) >>> print(calendar.name) VCALENDAR >>> print(calendar.prodid) -//Example Inc.//Example Calendar//EN >>> event = calendar.events[0] >>> print(event.summary) Planning meeting
- classmethod fromkeys(iterable, value=None)#
Create a new ordered dictionary with keys from iterable and values set to value.
- get(key, default=None)#
Get property value with default.
- classmethod get_component_class(name)#
Return a component with this name.
- get_inline(name, decode=1)#
Returns a list of values (split on comma).
- ignore_exceptions: ClassVar[bool] = False#
Whether or not to ignore exceptions when parsing.
If
True, and this component can't be parsed, then it will silently ignore it, rather than let the exception propagate upwards.
- inclusive: ClassVar[tuple[str] | tuple[tuple[str, str]]] = ()#
These properties are inclusive.
In other words, if the first property in the tuple occurs, then the second one must also occur.
Example
('duration', 'repeat')
- is_empty()#
Returns True if Component has no items or subcomponents, else False.
- is_thunderbird()#
Whether this component has attributes that indicate that Mozilla Thunderbird created it.
- Return type:
- items()#
Return a set-like object providing a view on the dict's items.
- keys()#
Return a set-like object providing a view on the dict's keys.
- property last_modified: datetime#
Datetime when the information associated with the component was last revised.
Since
LAST_MODIFIEDis an optional property, this returnsDTSTAMPifLAST_MODIFIEDis not set.
- property links: list[vUri | vUid | vXmlReference]#
LINK properties as a list.
- Purpose:
LINK provides a reference to external information related to a component.
- Property Parameters:
The VALUE parameter is required. Non-standard, link relation type, format type, label, and language parameters can also be specified on this property. The LABEL parameter is defined in RFC 7986.
- Conformance:
This property can be specified zero or more times in any iCalendar component. LINK is specified in RFC 9253. The LINKREL parameter is required.
- Description:
When used in a component, the value of this property points to additional information related to the component. For example, it may reference the originating web server.
This property is a serialization of the model in RFC 8288, where the link target is carried in the property value, the link context is the containing calendar entity, and the link relation type and any target attributes are carried in iCalendar property parameters.
The LINK property parameters map to RFC 8288 attributes as follows:
- LABEL
This parameter maps to the "title" attribute defined in Section 3.4.1 of RFC 8288. LABEL is used to label the destination of a link such that it can be used as a human-readable identifier (e.g., a menu entry) in the language indicated by the LANGUAGE (if present).
- LANGUAGE
This parameter maps to the "hreflang" attribute defined in Section 3.4.1 of RFC 8288. See RFC 5646. Example:
en,de-ch.- LINKREL
This parameter maps to the link relation type defined in Section 2.1 of RFC 8288. See Registered Link Relation Types.
- FMTTYPE
This parameter maps to the "type" attribute defined in Section 3.4.1 of RFC 8288.
There is no mapping for "title*", "anchor", "rev", or "media" RFC 8288.
Examples
The following is an example of this property, which provides a reference to the source for the calendar object.
LINK;LINKREL=SOURCE;LABEL=Venue;VALUE=URI: https://example.com/events
The following is an example of this property, which provides a reference to an entity from which this one was derived. The link relation is a vendor-defined value.
LINK;LINKREL="https://example.com/linkrel/derivedFrom"; VALUE=URI: https://example.com/tasks/01234567-abcd1234.ics
The following is an example of this property, which provides a reference to a fragment of an XML document. The link relation is a vendor-defined value.
LINK;LINKREL="https://example.com/linkrel/costStructure"; VALUE=XML-REFERENCE: https://example.com/xmlDocs/bidFramework.xml #xpointer(descendant::CostStruc/range-to( following::CostStrucEND[1]))
Set a link
icalendar.vUrito the event page:>>> from icalendar import Event, vUri >>> from datetime import datetime >>> link = vUri( ... "http://example.com/event-page", ... params={"LINKREL":"SOURCE"} ... ) >>> event = Event.new( ... start=datetime(2025, 9, 17, 12, 0), ... summary="An Example Event with a page" ... ) >>> event.links = [link] >>> print(event.to_ical()) BEGIN:VEVENT SUMMARY:An Example Event with a page DTSTART:20250917T120000 DTSTAMP:20250517T080612Z UID:d755cef5-2311-46ed-a0e1-6733c9e15c63 LINK;LINKREL="SOURCE":http://example.com/event-page END:VEVENT
- property location: str | None#
The intended venue for the activity defined by a calendar component.
- Property Parameters:
IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.
- Conformance:
Since RFC 5545, this property can be specified in "VEVENT" or "VTODO" calendar component. RFC 7953 adds this property to "VAVAILABILITY" and "VAVAILABLE".
- Description:
Specific venues such as conference or meeting rooms may be explicitly specified using this property. An alternate representation may be specified that is a URI that points to directory information with more structured specification of the location. For example, the alternate representation may specify either an LDAP URL RFC 4516 pointing to an LDAP server entry or a CID URL RFC 2392 pointing to a MIME body part containing a Virtual-Information Card (vCard) RFC 2426 for the location.
- move_to_end(key, last=True)#
Move an existing element to the end (or beginning if last is false).
Raise KeyError if the element does not exist.
- name: ClassVar[str | None] = 'AVAILABLE'#
The name of the component.
This should be defined in each component class.
Example:
VCALENDAR.
- classmethod new(categories=(), comments=None, concepts=None, contacts=None, created=None, description=None, end=None, last_modified=None, links=None, location=None, refids=None, related_to=None, sequence=None, stamp=None, start=None, summary=None, uid=None)[source]#
Create a new Available component with all required properties.
This creates a new Available component in accordance with RFC 7953.
- Parameters:
categories (
Sequence[str]) – Thecategoriesof the Available component.comments (
list[str] |str|None) – Thecommentsof the Available component.concepts (
list[vUri|str] |str|vUri|None) – Theconceptsof the Available component.contacts (
list[str] |str|None) – Thecontactsof the Available component.created (
date|None) – Thecreatedof the Available component.description (
str|None) – Thedescriptionof the Available component.last_modified (
date|None) – Thelast_modifiedof the Available component.links (
str|vUri|vUid|vXmlReference|None|list[str|vUri|vUid|vXmlReference]) – Thelinksof the Available component.location (
str|None) – Thelocationof the Available component.refids (
list[str] |str|None) –refidsof the Available component.related_to (
None|str|vText|vUri|vUid|list[str|vText|vUri|vUid]) –related_toof the Available component.sequence (
int|None) – Thesequenceof the Available component.stamp (
date|None) – Thestampof the Available component. If None, this is set to the current time.start (
datetime|None) – Thestartof the Available component.summary (
str|None) – Thesummaryof the Available component.uid (
str|UUID|None) – Theuidof the Available component. If None, this is set to a newuuid.uuid4().
- Returns:
- Raises:
InvalidCalendar – If the content is not valid according to RFC 7953.
Warning
As time progresses, we will be stricter with the validation.
- property_items(recursive=True, sorted=True)#
Returns properties in this component and subcomponents as: [(name, value), …]
- property rdates: list[tuple[date, None] | tuple[datetime, None] | tuple[datetime, datetime]]#
The RDATE property defines the list of DATE-TIME values for recurring components.
RDATE is defined in RFC 5545. The return value is a list of tuples
(start, end).startcan be adatetime.dateor adatetime.datetime, with and without timezone.endisNoneif the end is not specified and adatetime.datetimeif the end is specified.- Value Type:
The default value type for this property is DATE-TIME. The value type can be set to DATE or PERIOD.
- Property Parameters:
IANA, non-standard, value data type, and time zone identifier property parameters can be specified on this property.
- Conformance:
This property can be specified in recurring "VEVENT", "VTODO", and "VJOURNAL" calendar components as well as in the "STANDARD" and "DAYLIGHT" sub-components of the "VTIMEZONE" calendar component.
- Description:
This property can appear along with the "RRULE" property to define an aggregate set of repeating occurrences. When they both appear in a recurring component, the recurrence instances are defined by the union of occurrences defined by both the "RDATE" and "RRULE".
The recurrence dates, if specified, are used in computing the recurrence set. The recurrence set is the complete set of recurrence instances for a calendar component. The recurrence set is generated by considering the initial "DTSTART" property along with the "RRULE", "RDATE", and "EXDATE" properties contained within the recurring component. The "DTSTART" property defines the first instance in the recurrence set. The "DTSTART" property value SHOULD match the pattern of the recurrence rule, if specified. The recurrence set generated with a "DTSTART" property value that doesn't match the pattern of the rule is undefined. The final recurrence set is generated by gathering all of the start DATE-TIME values generated by any of the specified "RRULE" and "RDATE" properties, and then excluding any start DATE-TIME values specified by "EXDATE" properties. This implies that start DATE-TIME values specified by "EXDATE" properties take precedence over those specified by inclusion properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are generated by the "RRULE" and "RDATE" properties, only one recurrence is considered. Duplicate instances are ignored.
Example
Below, we set one RDATE in a list and get the resulting tuple of start and end.
>>> from icalendar import Event >>> from datetime import datetime >>> event = Event() # Add a list of recurrence dates >>> event.add("RDATE", [datetime(2025, 4, 28, 16, 5)]) >>> event.rdates [(datetime.datetime(2025, 4, 28, 16, 5), None)]
Note
You cannot modify the RDATE value by modifying the result. Use
icalendar.cal.Component.add()to add values.If you want to compute recurrences, have a look at Related Projects.
- property refids: list[str]#
REFID
- Purpose:
REFID acts as a key for associated iCalendar entities.
- Conformance:
Since RFC 9253, this property can be specified zero or more times in any iCalendar component.
- Description:
The value of this property is free-form text that creates an identifier for associated components. All components that use the same REFID value are associated through that value and can be located or retrieved as a group. For example, all of the events in a travel itinerary would have the same REFID value, so as to be grouped together.
Examples
The following is an example of this property.
REFID:itinerary-2014-11-17
Use a REFID to associate several VTODOs:
>>> from icalendar import Todo >>> todo_1 = Todo.new( ... summary="turn off stove", ... refids=["travel", "alps"] ... ) >>> todo_2 = Todo.new( ... summary="pack backpack", ... refids=["travel", "alps"] ... ) >>> todo_1.refids == todo_2.refids True
Note
List modifications do not modify the component.
- classmethod register(component_class)#
Register a custom component class.
- Parameters:
component_class (
type[Component]) – Component subclass to register. Must have anameattribute.- Raises:
ValueError – If
component_classhas nonameattribute.ValueError – If a component with this name is already registered.
- Return type:
Examples
Create a custom icalendar component with the name
X-EXAMPLE:>>> from icalendar import Component >>> class XExample(Component): ... name = "X-EXAMPLE" ... def custom_method(self): ... return "custom" >>> Component.register(XExample)
RELATED-TO properties as a list.
- Purpose:
This property is used to represent a relationship or reference between one calendar component and another. RFC 9523 allows URI or UID values and a GAP parameter.
- Value Type:
- Conformance:
Since RFC 5545. this property can be specified in the "VEVENT", "VTODO", and "VJOURNAL" calendar components. Since RFC 9523, this property MAY be specified in any iCalendar component.
- Description (RFC 5545):
The property value consists of the persistent, globally unique identifier of another calendar component. This value would be represented in a calendar component by the "UID" property.
By default, the property value points to another calendar component that has a PARENT relationship to the referencing object. The "RELTYPE" property parameter is used to either explicitly state the default PARENT relationship type to the referenced calendar component or to override the default PARENT relationship type and specify either a CHILD or SIBLING relationship. The PARENT relationship indicates that the calendar component is a subordinate of the referenced calendar component. The CHILD relationship indicates that the calendar component is a superior of the referenced calendar component. The SIBLING relationship indicates that the calendar component is a peer of the referenced calendar component.
Changes to a calendar component referenced by this property can have an implicit impact on the related calendar component. For example, if a group event changes its start or end date or time, then the related, dependent events will need to have their start and end dates changed in a corresponding way. Similarly, if a PARENT calendar component is cancelled or deleted, then there is an implied impact to the related CHILD calendar components. This property is intended only to provide information on the relationship of calendar components. It is up to the target calendar system to maintain any property implications of this relationship.
- Description (RFC 9253):
By default or when VALUE=UID is specified, the property value consists of the persistent, globally unique identifier of another calendar component. This value would be represented in a calendar component by the UID property.
By default, the property value points to another calendar component that has a PARENT relationship to the referencing object. The RELTYPE property parameter is used to either explicitly state the default PARENT relationship type to the referenced calendar component or to override the default PARENT relationship type and specify either a CHILD or SIBLING relationship or a temporal relationship.
The PARENT relationship indicates that the calendar component is a subordinate of the referenced calendar component. The CHILD relationship indicates that the calendar component is a superior of the referenced calendar component. The SIBLING relationship indicates that the calendar component is a peer of the referenced calendar component.
To preserve backwards compatibility, the value type MUST be UID when the PARENT, SIBLING, or CHILD relationships are specified.
The FINISHTOSTART, FINISHTOFINISH, STARTTOFINISH, or STARTTOSTART relationships define temporal relationships, as specified in the RELTYPE parameter definition.
The FIRST and NEXT define ordering relationships between calendar components.
The DEPENDS-ON relationship indicates that the current calendar component depends on the referenced calendar component in some manner. For example, a task may be blocked waiting on the other, referenced, task.
The REFID and CONCEPT relationships establish a reference from the current component to the referenced component. Changes to a calendar component referenced by this property can have an implicit impact on the related calendar component. For example, if a group event changes its start or end date or time, then the related, dependent events will need to have their start and end dates and times changed in a corresponding way. Similarly, if a PARENT calendar component is canceled or deleted, then there is an implied impact to the related CHILD calendar components. This property is intended only to provide information on the relationship of calendar components.
Deletion of the target component, for example, the target of a FIRST, NEXT, or temporal relationship, can result in broken links.
It is up to the target calendar system to maintain any property implications of these relationships.
Examples
RFC 5545 examples of this property:
RELATED-TO:jsmith.part7.19960817T083000.xyzMail@example.com
RELATED-TO:19960401-080045-4000F192713-0052@example.com
RFC 9253 examples of this property:
RELATED-TO;VALUE=URI;RELTYPE=STARTTOFINISH: https://example.com/caldav/user/jb/cal/ 19960401-080045-4000F192713.ics
See also
icalendar.enum.RELTYPE.
- property rrules: list[vRecur]#
RRULE defines a rule or repeating pattern for recurring components.
RRULE is defined in RFC 5545. RFC 7529 adds the
SKIPparametericalendar.prop.vSkip.- Property Parameters:
IANA and non-standard property parameters can be specified on this property.
- Conformance:
This property can be specified in recurring "VEVENT", "VTODO", and "VJOURNAL" calendar components as well as in the "STANDARD" and "DAYLIGHT" sub-components of the "VTIMEZONE" calendar component, but it SHOULD NOT be specified more than once. The recurrence set generated with multiple "RRULE" properties is undefined.
- Description:
The recurrence rule, if specified, is used in computing the recurrence set. The recurrence set is the complete set of recurrence instances for a calendar component. The recurrence set is generated by considering the initial "DTSTART" property along with the "RRULE", "RDATE", and "EXDATE" properties contained within the recurring component. The "DTSTART" property defines the first instance in the recurrence set. The "DTSTART" property value SHOULD be synchronized with the recurrence rule, if specified. The recurrence set generated with a "DTSTART" property value not synchronized with the recurrence rule is undefined. The final recurrence set is generated by gathering all of the start DATE-TIME values generated by any of the specified "RRULE" and "RDATE" properties, and then excluding any start DATE-TIME values specified by "EXDATE" properties. This implies that start DATE- TIME values specified by "EXDATE" properties take precedence over those specified by inclusion properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are generated by the "RRULE" and "RDATE" properties, only one recurrence is considered. Duplicate instances are ignored.
The "DTSTART" property specified within the iCalendar object defines the first instance of the recurrence. In most cases, a "DTSTART" property of DATE-TIME value type used with a recurrence rule, should be specified as a date with local time and time zone reference to make sure all the recurrence instances start at the same local time regardless of time zone changes.
If the duration of the recurring component is specified with the "DTEND" or "DUE" property, then the same exact duration will apply to all the members of the generated recurrence set. Else, if the duration of the recurring component is specified with the "DURATION" property, then the same nominal duration will apply to all the members of the generated recurrence set and the exact duration of each recurrence instance will depend on its specific start time. For example, recurrence instances of a nominal duration of one day will have an exact duration of more or less than 24 hours on a day where a time zone shift occurs. The duration of a specific recurrence may be modified in an exception component or simply by using an "RDATE" property of PERIOD value type.
Examples
Daily for 10 occurrences:
>>> from icalendar import Event >>> from datetime import datetime >>> from zoneinfo import ZoneInfo >>> event = Event() >>> event.start = datetime(1997, 9, 2, 9, 0, tzinfo=ZoneInfo("America/New_York")) >>> event.add("RRULE", "FREQ=DAILY;COUNT=10") >>> print(event.to_ical()) BEGIN:VEVENT DTSTART;TZID=America/New_York:19970902T090000 RRULE:FREQ=DAILY;COUNT=10 END:VEVENT >>> event.rrules [vRecur({'FREQ': ['DAILY'], 'COUNT': [10]})]
Daily until December 24, 1997:
>>> from icalendar import Event, vRecur >>> from datetime import datetime >>> from zoneinfo import ZoneInfo >>> event = Event() >>> event.start = datetime(1997, 9, 2, 9, 0, tzinfo=ZoneInfo("America/New_York")) >>> event.add("RRULE", vRecur({"FREQ": ["DAILY"]}, until=datetime(1997, 12, 24, tzinfo=ZoneInfo("UTC")))) >>> print(event.to_ical()) BEGIN:VEVENT DTSTART;TZID=America/New_York:19970902T090000 RRULE:FREQ=DAILY;UNTIL=19971224T000000Z END:VEVENT >>> event.rrules [vRecur({'FREQ': ['DAILY'], 'UNTIL': [datetime.datetime(1997, 12, 24, 0, 0, tzinfo=ZoneInfo(key='UTC'))]})]
Note
You cannot modify the RRULE value by modifying the result. Use
icalendar.cal.Component.add()to add values.If you want to compute recurrences, have a look at Related Projects.
- property sequence: int#
This property defines the revision sequence number of the calendar component within a sequence of revisions.
- Value Type:
INTEGER
- Property Parameters:
IANA and non-standard property parameters can be specified on this property.
- Conformance:
The property can be specified in "VEVENT", "VTODO", or "VJOURNAL" calendar component.
- Description:
When a calendar component is created, its sequence number is 0. It is monotonically incremented by the "Organizer's" CUA each time the "Organizer" makes a significant revision to the calendar component.
The "Organizer" includes this property in an iCalendar object that it sends to an "Attendee" to specify the current version of the calendar component.
The "Attendee" includes this property in an iCalendar object that it sends to the "Organizer" to specify the version of the calendar component to which the "Attendee" is referring.
A change to the sequence number is not the mechanism that an "Organizer" uses to request a response from the "Attendees". The "RSVP" parameter on the "ATTENDEE" property is used by the "Organizer" to indicate that a response from the "Attendees" is requested.
Recurrence instances of a recurring component MAY have different sequence numbers.
Examples
The following is an example of this property for a calendar component that was just created by the "Organizer":
>>> from icalendar import Event >>> event = Event() >>> event.sequence 0
The following is an example of this property for a calendar component that has been revised 10 different times by the "Organizer":
>>> from icalendar import Calendar >>> calendar = Calendar.example("issue_156_RDATE_with_PERIOD_TZID_khal") >>> event = calendar.events[0] >>> event.sequence 10
- set_inline(name, values, encode=1)#
Converts a list of values into comma separated string and sets value to that.
- property stamp: datetime | None#
The DTSTAMP property. datetime in UTC
All values will be converted to a datetime in UTC. RFC 5545:
Conformance: This property MUST be included in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components.
Description: In the case of an iCalendar object that specifies a "METHOD" property, this property specifies the date and time that the instance of the iCalendar object was created. In the case of an iCalendar object that doesn't specify a "METHOD" property, this property specifies the date and time that the information associated with the calendar component was last revised in the calendar store.
The value MUST be specified in the UTC time format.
In the case of an iCalendar object that doesn't specify a "METHOD" property, this property is equivalent to the "LAST-MODIFIED" property.
- property start: datetime | None#
The DTSTART property. datetime in UTC
All values will be converted to a datetime in UTC. Start of the component.
This is almost the same as
Event.DTSTARTwith one exception: The values MUST have a timezone and DATE is not allowed.- Description:
RFC 7953: If specified, the "DTSTART" and "DTEND" properties in "VAVAILABILITY" components and "AVAILABLE" subcomponents MUST be "DATE-TIME" values specified as either the date with UTC time or the date with local time and a time zone reference.
- property summary: str | None#
SUMMARY defines a short summary or subject for the calendar component.
- Property Parameters:
IANA, non-standard, alternate text representation, and language property parameters can be specified on this property.
- Conformance:
The property can be specified in "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar components.
- Description:
This property is used in the "VEVENT", "VTODO", and "VJOURNAL" calendar components to capture a short, one-line summary about the activity or journal entry.
This property is used in the "VALARM" calendar component to capture the subject of an EMAIL category of alarm.
Examples
The following is an example of this property:
SUMMARY:Department Party
- to_ical(sorted=True)#
- Parameters:
sorted (
bool) – Whether parameters and properties should be lexicographically sorted.
- to_jcal()#
Convert this component to a jCal object.
- Return type:
- Returns:
jCal object
See also
to_json.In this example, we create a simple VEVENT component and convert it to jCal:
>>> from icalendar import Event >>> from datetime import date >>> from pprint import pprint >>> event = Event.new(summary="My Event", start=date(2025, 11, 22)) >>> pprint(event.to_jcal()) ['vevent', [['dtstamp', {}, 'date-time', '2025-05-17T08:06:12Z'], ['summary', {}, 'text', 'My Event'], ['uid', {}, 'text', 'd755cef5-2311-46ed-a0e1-6733c9e15c63'], ['dtstart', {}, 'date', '2025-11-22']], []]
- to_json()#
Return this component as a jCal JSON string.
- Return type:
- Returns:
JSON string
See also
to_jcal.
- types_factory: ClassVar[TypesFactory] = {'ADR': <class 'icalendar.prop.adr.vAdr'>, 'BINARY': <class 'icalendar.prop.binary.vBinary'>, 'BOOLEAN': <class 'icalendar.prop.boolean.vBoolean'>, 'CAL-ADDRESS': <class 'icalendar.prop.cal_address.vCalAddress'>, 'CATEGORIES': <class 'icalendar.prop.categories.vCategory'>, 'DATE': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'DATE-TIME': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'DATE-TIME-LIST': <class 'icalendar.prop.dt.list.vDDDLists'>, 'DURATION': <class 'icalendar.prop.dt.types.vDDDTypes'>, 'FLOAT': <class 'icalendar.prop.float.vFloat'>, 'GEO': <class 'icalendar.prop.geo.vGeo'>, 'INLINE': <class 'icalendar.prop.inline.vInline'>, 'INTEGER': <class 'icalendar.prop.integer.vInt'>, 'N': <class 'icalendar.prop.n.vN'>, 'ORG': <class 'icalendar.prop.org.vOrg'>, 'PERIOD': <class 'icalendar.prop.dt.period.vPeriod'>, 'RECUR': <class 'icalendar.prop.recur.recur.vRecur'>, 'TEXT': <class 'icalendar.prop.text.vText'>, 'TIME': <class 'icalendar.prop.dt.time.vTime'>, 'UID': <class 'icalendar.prop.uid.vUid'>, 'UNKNOWN': <class 'icalendar.prop.unknown.vUnknown'>, 'URI': <class 'icalendar.prop.uri.vUri'>, 'UTC-OFFSET': <class 'icalendar.prop.dt.utc_offset.vUTCOffset'>, 'XML-REFERENCE': <class 'icalendar.prop.xml_reference.vXmlReference'>}#
- property uid: str#
UID specifies the persistent, globally unique identifier for a component.
We recommend using
uuid.uuid4()to generate new values.- Returns:
The value of the UID property as a string or
""if no value is set.
- Description:
The "UID" itself MUST be a globally unique identifier. The generator of the identifier MUST guarantee that the identifier is unique.
This is the method for correlating scheduling messages with the referenced "VEVENT", "VTODO", or "VJOURNAL" calendar component. The full range of calendar components specified by a recurrence set is referenced by referring to just the "UID" property value corresponding to the calendar component. The "RECURRENCE-ID" property allows the reference to an individual instance within the recurrence set.
This property is an important method for group-scheduling applications to match requests with later replies, modifications, or deletion requests. Calendaring and scheduling applications MUST generate this property in "VEVENT", "VTODO", and "VJOURNAL" calendar components to assure interoperability with other group- scheduling applications. This identifier is created by the calendar system that generates an iCalendar object.
Implementations MUST be able to receive and persist values of at least 255 octets for this property, but they MUST NOT truncate values in the middle of a UTF-8 multi-octet sequence.
RFC 7986 states that UID can be used, for example, to identify duplicate calendar streams that a client may have been given access to. It can be used in conjunction with the "LAST-MODIFIED" property also specified on the "VCALENDAR" object to identify the most recent version of a calendar.
- Conformance:
RFC 5545 states that the "UID" property can be specified on "VEVENT", "VTODO", and "VJOURNAL" calendar components. RFC 7986 modifies the definition of the "UID" property to allow it to be defined in an iCalendar object. RFC 9074 adds a "UID" property to "VALARM" components to allow a unique identifier to be specified. The value of this property can then be used to refer uniquely to the "VALARM" component.
This property can be specified once only.
- Security:
RFC 7986 states that UID values MUST NOT include any data that might identify a user, host, domain, or any other security- or privacy-sensitive information. It is RECOMMENDED that calendar user agents now generate "UID" values that are hex-encoded random Universally Unique Identifier (UUID) values as defined in Sections 4.4 and 4.5 of RFC 4122. You can use the
uuidmodule to generate new UUIDs.- Compatibility:
For Alarms,
X-ALARMUIDis also considered.
Examples
The following is an example of such a property value:
5FC53010-1267-4F8E-BC28-1D7AE55A7C99.Set the UID of a calendar:
>>> from icalendar import Calendar >>> from uuid import uuid4 >>> calendar = Calendar() >>> calendar.uid = uuid4() >>> print(calendar.to_ical()) BEGIN:VCALENDAR UID:d755cef5-2311-46ed-a0e1-6733c9e15c63 END:VCALENDAR
- values()#
Return an object providing a view on the dict's values.
- walk(name=None, select=<function Component.<lambda>>)#
Recursively traverses component and subcomponents. Returns sequence of same. If name is passed, only components with name will be returned.