README

RecSQL’s basic idea is to treat numpy record arrays like SQL tables. What it does, in fact, is to represent the arrays as real SQL tables (using SQLite) and provide convenience functions to return recarrays on demand.

This works ok for small tables but less so if you want to access gigabytes of data as recarrays. It’s a hack.

Documentation can be found at http://recsql.readthedocs.org/

Example

>>> from recsql import SQLarray
>>> import numpy
>>> a = numpy.rec.fromrecords(numpy.arange(100).reshape(25,4), names='a,b,c,d')
>>> Q = SQLarray('my_name', a)
>>> print repr(Q.recarray)
rec.array([(0, 1, 2, 3), (4, 5, 6, 7), (8, 9, 10, 11), (12, 13, 14, 15),
       (16, 17, 18, 19), (20, 21, 22, 23), (24, 25, 26, 27),
       (28, 29, 30, 31), (32, 33, 34, 35), (36, 37, 38, 39),
       (40, 41, 42, 43), (44, 45, 46, 47), (48, 49, 50, 51),
       (52, 53, 54, 55), (56, 57, 58, 59), (60, 61, 62, 63),
       (64, 65, 66, 67), (68, 69, 70, 71), (72, 73, 74, 75),
       (76, 77, 78, 79), (80, 81, 82, 83), (84, 85, 86, 87),
       (88, 89, 90, 91), (92, 93, 94, 95), (96, 97, 98, 99)],
      dtype=[('a', '<i4'), ('b', '<i4'), ('c', '<i4'), ('d', '<i4')])
>>> Q.SELECT('*', 'WHERE a < 10 AND b > 5')
rec.array([(8, 9, 10, 11)],
    dtype=[('a', '<i4'), ('b', '<i4'), ('c', '<i4'), ('d', '<i4')])
# creating new SQLarrays:
>>> R = Q.selection('a < 20 AND b > 5')
>>> print R
<recsql.sqlarray.SQLarray object at 0x...>

Availability

The latest version of the package is being made available via the internet at https://github.com/orbeckst/RecSQL

RecSQL is also listed on PyPi http://pypi.python.org/pypi/RecSQL and can thus be installed with

pip install RecSQL

See INSTALL for further installation instructions.

A git repository of the package is hosted at http://github.com/orbeckst/RecSQL .

Getting Involved

Please submit problems, questions and questions through the issue tracker https://github.com/orbeckst/RecSQL/issues . Pull requests are also very welcome.

Table Of Contents

Previous topic

RecSQL – simple SQL analysis of python records

Next topic

INSTALL

This Page