Process branch data by ‘JSONData’¶
The class JSONData provides operations on data structures. The class hierarchy is hereby reduced to a top-node representation JSONDATA of JSONDataSerializer, while the branches are allocated and processed as native Python data elements. Thus the perfomance impact of JSONData is kept minimal, basically negligible.
Provided syntax elements are:
native access attributes:
The node addresses for the native access to the JSON in-memory representation. The data format is compatible to the packages ‘json’ and ‘jsonschema’, e.g. also to ‘ujson’. Thus provides native Python access performance.
branch operations:
Handle complete sub structures as logical branches of a main JSON document. The interface is designed in accordance to RFC6902 with extension for Python specifics.
tree utilities:
Generic tree functions for the provided in-memory representation by ‘json’ and ‘jsonschema’ are available as jsondatadiff [jsondatadiff] and jsondatafind [jsondatafind].
Syntax Elements¶
The current release provides for branches the class ‘JSONData’ with basic set operations for branches,
Data¶
Native JSON representation access attributes:
attr := data, schema
This package supports in the current version the following data types:
| JSON | Python |
|---|---|
| object | dict |
| array | list |
| string | unicode |
| number (int) | int, long |
| number (real) | float |
| true | True |
| false | False |
| null | None |
It also understands NaN, Infinity, and
-Infinity as their corresponding float
values, which is outside the JSON spec.
The supported standard value types for Python of get_node_value() are mapped automatically as depicted in the following table. Additional bindings may be implemented by sub-classing.
| JSONPointer(jsondata) | Python-valtype |
|---|---|
| object (dict) | dict |
| array (list) | list |
| array (tuple) | list |
| string | unicode |
| number (int) | int |
| number (long) | long |
| number (float) | float |
| *number (double) | float |
| number (octal) | int |
| number (hex) | int |
| number (binary) | int |
| number (complex) | – (custom) |
| true | True |
| false | False |
| null | None |
The mappings in detail are:
object(dict) => dict:
1
{a:b} - native Python dictionaryarray(list) => list:
1
[a,b] - native Python list
(*)array(tuple) => list:
1
(a,b) - native Python list
string(str) => unicode”
1
"abc" - native Python unicode string UTF-8
number(int) => int:
1
1234, −24, 0 - Integers (unlimited precision)
number(long) => int:
1
1234, −24, 0 - Integers (unlimited precision)
number(float) => float:
1
1.23, 3.14e-10, 4E210, 4.0e+210, 1., .1 - Floating-point
Normally implemented as C doubles in CPython.
(*)number(double) => float:
1
1.23, 3.14e-10, 4E210, 4.0e+210, 1., .1 - Floating-point
Normally implemented as C doubles in CPython.
number(octal) => int:
1
0o177 - Octal, hex, and binary literals for integers
number(hex) => int:
1
0x9ff - Octal, hex, and binary literals for integers
number(binary) => int:
1
0b1111 - Octal, hex, and binary literals for integers
number(complex) => <not-supported>(requires custom):
1
3+4j, 3.0+4.0j, 3J - Complex numbers
true(True) => boolean(True):
1
True - native Python boolean
false(False) => boolean(False):
1
False - native Python boolean
null(None) => None(None):
1
False - native Python None
The specification RFC4627 [RFC4627] and the updated RFC7159 [RFC7159] define different valid top-level nodes.
- RFC4627: top-level must be object or array
- RFC7159: any valid node type is permitted as top-level, including null
This behaviour is provided by the jsondata package by setting the mode parameter appropriately.
Administrative Operations¶
Branch operations(branch_<ops>), see RFC6902:
ops := branch_add | branch_copy | branch_create | branch_div
| branch_move | branch_remove | branch_replace
| branch_superpose | branch_test
Logic Operators¶
The logic operators provide basic set operations. The scope of the operations is the top level keys of the branch, deep level operations are supported by the interfaces of type branch_*.
Operators for the set calculation of branches
ops := '&' | '|' | '^' #
