grapple 0.2.2

Installation

The easiest way to install Grapple is using pip:

pip install grapple

Grapple is designed to integrate with PostgreSQL, using connection information in config.py. By default, it assumes that your database is located on localhost (127.0.0.1), and that your database’s name, password, username and are all “grapple”.

(While this is certainly not a secure setup, it may be convenient for people who install Grapple via pip, and do not wish to edit its source code.)

Usage

Grapple can be used as a Python module:

from grapple import Grapple

grapple = Grapple()
grapple.download()

The Grapple constructor accepts the following keyword arguments:

socket_url (str):

rippled websocket URL (default=”ws://127.0.0.1:6006/”)

full (bool):

True if downloading the full ledger (starting from the current ledger and walking back to the genesis ledger). False if the download should stop at the last current ledger (i.e., the last time grapple was run). (default=True)

genesis (int):

Genesis block index and download halting point. (default=152370)

quiet (bool):

If True, suppress console output. (default=True)

resampling_frequencies (tuple):

Resampling frequencies, using pandas frequency codes. If None, then resampling is disabled. (default=(‘D’,) or daily)

It can also be run as a script:

python grapple.py [-flags]

Optional flags:

-w, --websocket [websocket url]:
    Specify the rippled websocket url. (default=ws://127.0.0.1:6006/)

-p, --public:
    Use Ripple Labs' public websocket, wss://s1.ripple.com:51233.

-f, --full:
    Download the full Ripple ledger.  Automatic on your first run.

-g, --genesis [ledger index]:
    Genesis ledger index and download halting point.

-q, --quiet:
    Suppress command line output.

Tests

Unit tests are in the test/ directory. Coverage is limited at the moment, but slowly improving!

Note: tests that require a local rippled and/or Postgres database connection are disabled by default. See test/test_grapple.py for details.