# otp.databases

### databases(context=utils.default, derived=False, readable_only=False, fetch_description=None, as_table=False)

Gets all available databases in the `context`.

* **Parameters:**
  * **context** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *,* *optional*) -- Context to run the query.
    If not set then default [`context`](../config.md#onetick.py.configuration.Config.context) is used.
    See [guide about switching contexts](../../static/getting_started/session.md#switching-contexts) for examples.
  * **derived** ([*bool*](https://docs.python.org/3/library/functions.html#bool) *,* [*dict*](https://docs.python.org/3/library/stdtypes.html#dict)) -- If False (default) then derived databases are not returned.
    Otherwise derived databases names are added to the result after the non-derived databases.
    If set to dict then its items used as parameters to [`derived_databases()`](derived_databases.md#onetick.py.derived_databases).
    If set to True then default parameters for [`derived_databases()`](derived_databases.md#onetick.py.derived_databases) are used.
  * **readable_only** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- 

    If set to True, then return only the databases with read-access for the current user.
    If set to False (default), return all databases visible from the current process.

    #### WARNING
    Setting this flag may introduce significant delay for query execution
    in some OneTick configurations and environments,
    because it has to check all accessible remote servers.
  * **fetch_description** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If set to True, retrieves descriptions for databases and puts them into `description` property of
    [`DB`](../session/db.md#onetick.py.DB) objects in a returned dict.
  * **as_table** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If False (default), this function returns a dictionary of database names and database objects.
    If True, returns a [pandas.DataFrame](https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.html) table where each row contains the info for each database.
* **Returns:**
  * Dict where keys are database names and values are [`DB`](db.md#onetick.py.db._inspection.DB) objects
  * or [pandas.DataFrame](https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.html) object depending on `as_table` parameter.
* **Return type:**
  [dict](https://docs.python.org/3/library/stdtypes.html#dict)[[str](https://docs.python.org/3/library/stdtypes.html#str), [*DB*](db.md#onetick.py.db._inspection.DB)] | *DataFrame*

### Examples

Get the dictionary of database names and objects:

```pycon
>>> otp.databases()  
{'ABU_DHABI': <onetick.py.db._inspection.DB at 0x7f9413a5e8e0>,
 'ABU_DHABI_BARS': <onetick.py.db._inspection.DB at 0x7f9413a5ef40>,
 'ABU_DHABI_DAILY': <onetick.py.db._inspection.DB at 0x7f9413a5eac0>,
 'ALPHA': <onetick.py.db._inspection.DB at 0x7f9413a5e940>,
 'ALPHA_X': <onetick.py.db._inspection.DB at 0x7f9413a5e490>,
 ...
}
```

Get a table with database info:

```pycon
>>> otp.databases(as_table=True)  
           Time            DB_NAME  READ_ACCESS  WRITE_ACCESS         ...
0    2003-01-01          ABU_DHABI            1             0         ...
1    2003-01-01     ABU_DHABI_BARS            1             1         ...
2    2003-01-01    ABU_DHABI_DAILY            1             1         ...
3    2003-01-01              ALPHA            1             1         ...
4    2003-01-01            ALPHA_X            1             1         ...
...         ...                ...          ...           ...         ...
```

#### SEE ALSO
**SHOW_DB_LIST** OneTick event processor
<br/>
**ACCESS_INFO** OneTick event processor
<br/>
[`derived_databases()`](derived_databases.md#onetick.py.derived_databases)
<br/>