Tables — selkie.pyx.table

A table is a persistent collection of objects of a fixed type. A table is associated with a file and with an object class. For example, suppose the contents of foo.tab is:

name Abc
age 120

name Def
age 87

And suppose that the class Foo is defined:

class Foo (object):

    def __init__ (self):
        self.name = ''
        self.age = ''

The class must permit the following pattern:

>>> foo = Foo()
>>> foo.name = 'Abc'
>>> foo.age = '120'

(Unfortunately, this is inconsistent with using namedtuple. The motivation is that we wish to permit objects having variable numbers of attributes specified.)

Then one may load and access the table as follows:

>>> foos = Table(Foo, 'foo.tab')
>>> foos[0].name
'Abc'

One may also index a table by column name (a string) or by an arbitrary key function:

>>> idx = Index(foos, 'name')
>>> foos['Def']
<Foo at 0x123123>

If the index key does not determine a unique record, one may specify multi=True, in which case the values are lists of objects.