diff options
Diffstat (limited to 'examples/elementtree')
| -rw-r--r-- | examples/elementtree/__init__.py | 23 | ||||
| -rw-r--r-- | examples/elementtree/adjacency_list.py | 10 | ||||
| -rw-r--r-- | examples/elementtree/optimized_al.py | 10 |
3 files changed, 18 insertions, 25 deletions
diff --git a/examples/elementtree/__init__.py b/examples/elementtree/__init__.py index 6462dd562..66e9cfbbe 100644 --- a/examples/elementtree/__init__.py +++ b/examples/elementtree/__init__.py @@ -7,26 +7,6 @@ native cElementTree as well as lxml, and can be adapted to suit any kind of DOM representation system. Querying along xpath-like strings is illustrated as well. -In order of complexity: - -* ``pickle.py`` - Quick and dirty, serialize the whole DOM into a BLOB - column. While the example is very brief, it has very limited - functionality. - -* ``adjacency_list.py`` - Each DOM node is stored in an individual - table row, with attributes represented in a separate table. The - nodes are associated in a hierarchy using an adjacency list - structure. A query function is introduced which can search for nodes - along any path with a given structure of attributes, basically a - (very narrow) subset of xpath. - -* ``optimized_al.py`` - Uses the same strategy as - ``adjacency_list.py``, but associates each DOM row with its owning - document row, so that a full document of DOM nodes can be loaded - using O(1) queries - the construction of the "hierarchy" is performed - after the load in a non-recursive fashion and is much more - efficient. - E.g.:: # parse an XML file and persist in the database @@ -39,4 +19,7 @@ E.g.:: # dump the XML print document +.. autosource:: + :files: pickle.py, adjacency_list.py, optimized_al.py + """
\ No newline at end of file diff --git a/examples/elementtree/adjacency_list.py b/examples/elementtree/adjacency_list.py index a3ad42778..5e27ba9ca 100644 --- a/examples/elementtree/adjacency_list.py +++ b/examples/elementtree/adjacency_list.py @@ -1,9 +1,17 @@ -"""illustrates an explicit way to persist an XML document expressed using ElementTree. +"""Illustrates an explicit way to persist an XML document expressed using ElementTree. + +Each DOM node is stored in an individual +table row, with attributes represented in a separate table. The +nodes are associated in a hierarchy using an adjacency list +structure. A query function is introduced which can search for nodes +along any path with a given structure of attributes, basically a +(very narrow) subset of xpath. This example explicitly marshals/unmarshals the ElementTree document into mapped entities which have their own tables. Compare to pickle.py which uses pickle to accomplish the same task. Note that the usage of both styles of persistence are identical, as is the structure of the main Document class. + """ ################################# PART I - Imports/Coniguration #################################### diff --git a/examples/elementtree/optimized_al.py b/examples/elementtree/optimized_al.py index 1dbad0943..e13f5b0ee 100644 --- a/examples/elementtree/optimized_al.py +++ b/examples/elementtree/optimized_al.py @@ -1,7 +1,9 @@ -"""This script duplicates adjacency_list.py, but optimizes the loading -of XML nodes to be based on a "flattened" datamodel. Any number of XML documents, -each of arbitrary complexity, can be loaded in their entirety via a single query -which joins on only three tables. +"""Uses the same strategy as + ``adjacency_list.py``, but associates each DOM row with its owning + document row, so that a full document of DOM nodes can be loaded + using O(1) queries - the construction of the "hierarchy" is performed + after the load in a non-recursive fashion and is more + efficient. """ |