# otp.RefData

### *class* RefData(ref_data_type=None, symbol=utils.adaptive, db=utils.adaptive_to_default, start=utils.adaptive, end=utils.adaptive, \*\*kwargs)

Bases: [`Source`](../source/root.md#onetick.py.Source)

Shows reference data for the specified security and reference data type.

It can be used to view corporation actions,
symbol name changes,
primary exchange info and symbology mapping for a securities,
as well as the list of symbologies,
names of custom adjustment types for corporate actions present in a reference database
as well as names of continuous contracts in database symbology.

* **Parameters:**
  * **ref_data_type** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) -- 

    Type of reference data to be queried. Possible values are:
    * corp_actions
    * symbol_name_history
    * primary_exchange
    * symbol_calendar
    * symbol_currency
    * symbology_mapping
    * symbology_list
    * custom_adjustment_type_list
    * all_calendars
    * all_continuous_contract_names
  * **symbol** (str, list of str, [`Source`](../source/root.md#onetick.py.Source), [`query`](../misc/query.md#onetick.py.query), [`eval query`](../misc/eval.md#onetick.py.eval)) -- Symbol(s) from which data should be taken.
  * **db** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) -- Name of the database.
  * **start** ([`otp.datetime`](../datetime/dt.md#onetick.py.datetime)) -- Start time for tick generation. By default the start time of the query will be used.
  * **end** ([`otp.datetime`](../datetime/dt.md#onetick.py.datetime)) -- End time for tick generation. By default the end time of the query will be used.

### Examples

Show calendars for a database TRAIN_A_PRL_TRD in the given range:

```pycon
>>> src = otp.RefData(
...     'all_calendars',
...     db='TRAIN_A_PRL_TRD',
...     start=otp.dt(2018, 2, 1),
...     end=otp.dt(2018, 2, 9),
... )  
>>> otp.run(src, symbol_date=otp.dt(2018, 2, 1))  
                 Time        END_DATETIME CALENDAR_NAME SESSION_NAME SESSION_FLAGS DAY_PATTERN  START_HHMMSS          END_HHMMSS TIMEZONE  PRIORITY DESCRIPTION
0 2018-02-01 00:00:00 2018-02-06 23:59:59          FRED      Regular             R   0.0.12345         93000              160000  EST5EDT         0
1 2018-02-06 23:59:59 2018-02-07 23:59:59          FRED      Holiday             H   0.0.12345         93000              160000  EST5EDT         1
2 2018-02-07 23:59:59 2050-12-31 23:59:59          FRED      Regular             F   0.0.12345         93000              160000  EST5EDT         0
```

#### SEE ALSO
**REF_DATA** OneTick event processor