crandas.base

class crandas.base.Session(base_path=None, **kwargs)

Bases: object

This object stores the state specific to the connection to the VDL server. By default, the connect() method is invoked lazily, on the first crandas method that requires a connection to the VDL. Because of this, the user can first configure the variables; for example:

>>> import crandas
>>> from crandas.base import session
>>> session.endpoint = "https://example.com:10000/api/v1"
>>> session.base_path = Path("/cranmera")
>>> crandas.DataFrame({})

Raises:

• ServerError – Passes through error from VDL and appropriate error code

• ServerError – Passes through error from VDL in case error code is not known

property base_path: Path | None

The base ‘cranmera’ folder. When None, the application tries to find a parent of the current directory called ‘cranmera’, or defaults to the current directory.

connect(connection_file=None)

Establishes a connection with the query server and verifies whether the client and server versions are compatible.

Parameters:

connection_file (str | Path | file-like object) –

A (path to a) VDL connection file.

It may be specified as string not containing slashes (/), backslashes () or dots (.), in which case it is interpreted as a “{name}.vdlconn” file located in the configuration folder. By default, the configuration folder is ~/.config/crandas – this can also be modified by some environment variables, see crandas.config.

If it is a string that contains slashes, backslashes or dots, it is assumed to be a path, either a relative path for the current working directory, or an absolute path.

read_analyst_key()

Read the analyst’s key, that is used to ensure that only some designated analysts can execute an approved query, for the current session.

reset()

Disconnects and resets the current session.

Use this command if the MPC servers have been restarted.