dictquery 0.2.0

Library to query python dicts

DictQuery
=========

Library to query python dicts

Several syntax examples:

::

"`age` >= 12"
"`user.name` == 'cyberlis'"
"`user.email` MATCH /\w+@\w+\.com/ AND `age` != 11"
"`user.frinds.age` > 12 AND `user.friends.name` LIKE 'Ra*ond'"
"`email` LIKE 'mariondelgado?bleendot?com'"
"`eyeColor` IN ['blue', 'green', 'black']"
"`isActive` AND (`gender` == 'female' OR `age` == 27)"
"`latitude` != `longitude`"

Supported data types
====================

+-----------+-----------------------------------+
| type | example |
+===========+===================================+
| KEY | \`name\`, \`age\` |
+-----------+-----------------------------------+
| NUMBER | 42, -12, 34.7 |
+-----------+-----------------------------------+
| STRING | 'hello', "hellow" |
+-----------+-----------------------------------+
| BOOLEAN | true, false |
+-----------+-----------------------------------+
| NONE | none, null |
+-----------+-----------------------------------+
| NOW | utc current datetime |
+-----------+-----------------------------------+
| REGEXP | /\\d+\\w+\\d+/ |
+-----------+-----------------------------------+
| ARRAY | list of any items and any types |
+-----------+-----------------------------------+

Dict keys
=========

Dict keys use back-ticks (\`\`)

DictQuery supports nested dicts splited by dot ``.`` or any separator
specified in ``key_separator`` param. Default ``key_separator='.'``

::

>>> import dictquery as dq
>>> dq.match(data, "`friends.age` <= 26")
True
>>> compiled = dq.compile("`friends/age` <= 26", key_separator='/')
>>> compiled.match(data)
True

if you don't need nested keys parsing and want get keys as is or if your
keys contain separator char, you can disable nested keys behaviour by
setting ``use_nested_keys=False``

::

>>> import dictquery as dq
>>> dq.match(data, "`user.address`")
False
>>> compiled = dq.compile("`user.address`", use_nested_keys=False)
>>> compiled.match(data)
True

In query you can use dict keys 'as is' without any binary operation.
DictQuery will get value by the key and evalute it to bool

::

>>> import dictquery as dq
>>> dq.match(data, "`isActive`")
False
>>> dq.match(data, "`isActive` == false")
True

if key is not found by default this situation evalutes to boolean
``False`` (no exception raised). You can set ``raise_keyerror=True`` to
raise keyerror if key would not be found.

::

>>> import dictquery as dq
>>> dq.match(data, "`favoriteFruit`")
False
>>> compiled = dq.compile("`favoriteFruit`", raise_keyerror=True)
>>> compiled.match(data)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "dictquery.py", line 355, in match
return self._eval_expr(query_dict, self.ast)
File "dictquery.py", line 327, in _eval_expr
dict_value = self._get_dict_value(query_dict, tree.value)
File "dictquery.py", line 302, in _get_dict_value
self.key_separator, self.raise_keyerror)
File "dictquery.py", line 258, in get_dict_value
raise DQKeyError("Key '%s' not found" % dict_key)
dictquery.DQKeyError: "Key 'favoriteFruit' not found"

Comparisons
===========

+-------------+-------------------------+
| Operation | Meaning |
+=============+=========================+
| < | strictly less than |
+-------------+-------------------------+
| <= | less than or equal |
+-------------+-------------------------+
| > | strictly greater than |
+-------------+-------------------------+
| >= | greater than or equal |
+-------------+-------------------------+
| == | equal |
+-------------+-------------------------+
| != | not equal |
+-------------+-------------------------+

::

>>> import dictquery as dq
>>> dq.match(data, "`age` == 26")
True
>>> dq.match(data, "`latitude` > 12")
True
>>> dq.match(data, "`longitude` < 30")
True
>>> dq.match(data, "`friends.age` <= 26")
True
>>> dq.match(data, "`longitude` >= -130")
True
>>> dq.match(data, "`id` != 0")
True
>>> dq.match(data, "`gender` == 'male'")
False

String comparisons and matching
===============================

String literals are written in a variety of ways: \* Single quotes:
'allows embedded "double" quotes' \* Double quotes: "allows embedded
'single' quotes".

+-------------+---------------------------------------+
| Operation | Meaning |
+=============+=======================================+
| MATCH | regexp matching |
+-------------+---------------------------------------+
| LIKE | glob like matching |
+-------------+---------------------------------------+
| IN | dict item substring in string |
+-------------+---------------------------------------+
| CONTAIN | dict item substring contains string |
+-------------+---------------------------------------+

< , <= , > , >= , == , != works same way with strings as python

::

>>> import dictquery as dq
>>> dq.match(data, "`eyeColor` == 'green'")
True
>>> dq.match(data, "`name.firstname` != 'Ratliff'")
True
>>> dq.match(data, "`eyeColor` IN 'string with green color'")
True
>>> dq.match(data, "`email` CONTAIN '.com'")
True
>>> dq.match(data, r"`email` MATCH /\w+@\w+\.\w+/")
True
>>> dq.match(data, r"`email` LIKE 'mariondelgado@*'")
True
>>> dq.match(data, r"`email` LIKE 'mariondelgado?bleendot?com'")
True

By default all string related operations are case sensitive. To change
this behaviour you have to create instance of DictQuery with
``case_sensitive=False``

::

>>> import dictquery as dq
>>> dq.match(data, "`name.firstname` == 'marion'")
False
>>> compiled = dq.compile("`name.firstname` == 'marion'", case_sensitive=False)
>>> compiled.match(data)
True

Array comparisons
=================

+-------------+------------------------------------+
| Operation | Meaning |
+=============+====================================+
| IN | dict item in array |
+-------------+------------------------------------+
| CONTAIN | dict item contains matching item |
+-------------+------------------------------------+

::

>>> import dictquery as dq
>>> dq.match(data, "`tags` CONTAIN 'dolor'")
True
>>> dq.match(data, "`eyeColor` IN ['blue', 'green', 'black']")
True

Key presence in dict
====================

``CONTAIN`` can be used with dict items to check if key in dict

::

>>> import dictquery as dq
>>> dq.match(data, "`name` CONTAIN 'firstname'")
True
>>> dq.match(data, "`name` CONTAIN 'thirdname'")
False

Datetime comparisons with ``NOW``
=================================

``NOW`` returns current utc datetime

dict item can be compared with ``NOW`` using standard operations (< , <=
, > , >= , == , !=)

::

>>> import dictquery as dq
>>> dq.match(data, "`registered` < NOW")
True
>>> dq.match(data, "`registered` != NOW")
True

Logical operators
=================

+------------+------------------------------------------------------+-----------+
| Operator | Meaning | Example |
+============+======================================================+===========+
| and | True if both the operands are true | x and y |
+------------+------------------------------------------------------+-----------+
| or | True if either of the operands is true | x or y |
+------------+------------------------------------------------------+-----------+
| not | True if operand is false (complements the operand) | not x |
+------------+------------------------------------------------------+-----------+

::

>>> import dictquery as dq
>>> dq.match(data, "`isActive` AND `gender` == 'female'")
False
>>> dq.match(data, "`isActive` OR `gender` == 'female'")
True
>>> dq.match(data, "NOT `isActive` AND `gender` == 'female'")
True

You can use parentheses to group statements or change evalution order

::

>>> import dictquery as dq
>>> dq.match(data, "`isActive` AND `gender` == 'female' OR `age` == 27")
True
>>> dq.match(data, "`isActive` AND (`gender` == 'female' OR `age` == 27)")
False


Data for examples above:
=================


::

from datetime import datetime
data = {
"_id": 10,
"isActive": False,
"age": 27,
"eyeColor": "green",
"name": {
"firstname": "Marion",
"secondname": "Delgado",
},
"gender": "female",
"email": "[e-mail]",
"registered": datetime.strptime("2015-03-29T06:07:58", "%Y-%m-%dT%H:%M:%S"),
"latitude": 74.785608,
"longitude": -112.366088,
"tags": [
"voluptate",
"ex",
"dolor",
"aute"
],
"user.address": "155 Village Road, Enetai, Puerto Rico, 2634",
"friends": [
{
"id": 0,
"name": {
"firstname": "Ratliff",
"secondname": "Becker",
},
"age": 27,
"eyeColor": "green"
},
{
"id": 1,
"name": {
"firstname": "Raymond",
"secondname": "Albert",
},
"age": 19,
"eyeColor": "brown"
},
{
"id": 2,
"name": {
"firstname": "Mavis",
"secondname": "Sheppard",
},
"age": 34,
"eyeColor": "blue"
}
]
}