dicteval

Library to evaluate expressions in dict/json objects.

Requirements

Python 3.6+

Basic Usage

Module dicteval will evaluate basic types with no modifications but it will evaluate dicts (or json objects) containing keys started with = (equal) symbol as an expression:

>>> from dicteval import dicteval
>>> dicteval(3)
3
>>> dicteval([3, 5])
[3, 5]
>>> dicteval((5, 3))
[5, 3]
>>> dicteval({"=sum": [3, 5]})
8
>>> dicteval({"=": 5})  # = symbol alone is a 'nop' function
5

You can provide a dictionary with context to be used during evaluation process.

>>> dicteval({"=": "!{var}"}, context={"var": 1.0})
1.0

You can also wrap your string content with @{} to force a Python eval() with the context provided:

>>> dicteval({"=sum": [3, "@{var + 2}"]}, context={"var": 3})
8

Functions

You can use the following builtin functions in your expressions:

Function =any

Returns True if any element of sequence is true.

>>> dicteval({"=any": [1, 2, 3]})
True
>>> dicteval({"=any": [0, 0]})
False

Function =eq

Returns True if all elements of sequence are equals:

>>> dicteval({"=eq": [1, 1, 1, 1]})
True

Function =if

Evaluates condition and returns first value if true, otherwise, returns second value. If no false value is supplied, it is assumed to be None.

>>> dicteval({"=if": [{"=": "@{var > 5}"}, "yes", "no"]}, context={"var": 6})
'yes'
>>> dicteval({"=if": [{"=": "@{var > 5}"}, "yes", "no"]}, context={"var": 4})
'no'
>>> dicteval({"=if": [{"=": "@{var > 5}"}, "yes"]}, context={"var": 4})

Function =neq

Returns True if elements of sequence are different:

>>> dicteval({"=neq": [1, 1, 1, 5]})
True

Function = (or nop)

Returns the same values passed as arguments:

>>> dicteval({"=": [1, 2, 3, 4]})
[1, 2, 3, 4]
>>> dicteval({"=nop": "spam"})
'spam'

Function =not

Returns the boolean inverse of argument:

>>> dicteval({"=not": False})
True
>>> dicteval({"=not": True})
False
>>> dicteval({"=not": None})
True
>>> dicteval({"=not": "XYZ"})
False

Function =sum

Returns a number with the sum of arguments:

>>> dicteval({"=sum": [3, 5]})
8

Function =mul

Returns a number with the product of arguments:

>>> dicteval({"=mul": [3, 5]})
15

Function =all

Return True if all elements of the iterable are true (or if the iterable is empty)

>>> dicteval({"=all": (True, False)})
False
>>> dicteval({"=all": (True, True)})
True

Function =divmod

Returns a tuple containing the quotient and remainder after division:

>>> dicteval({"=divmod": [8,3]})
(2, 2)
>>> dicteval({"=divmod": [7.5,2.5]})
(3.0, 0.0)

Function =zip

Return list of aggregate tuples constructed from elements of multiple iterables.

>>> dicteval({"=zip": [[1, 2, 3], [4, 5], [6, 7, 8, 9]]})
[(1, 4, 6), (2, 5, 7)]

To Do

Add more functions to the builtin language

Contribute

To contribute to dicteval:

Clone this repository and cd into it

Install dev dependencies with [pipenv](https://github.com/pypa/pipenv) `bash pipenv install --dev `

Create a branch, like git checkout -b [feature_name]

Git commit changes

Pull request

License

This software is licensed under MIT license.

Metadata

Release files for dicteval 0.0.6

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for dicteval 0.0.6
File	Size	Uploaded
dicteval-0.0.6.tar.gz	4.9 kB	Oct 25, 2018	Details

Built distribution (wheel)

Table of built distributions (wheels) for dicteval 0.0.6
File	Interpreter	ABI	Platform	Reset
dicteval-0.0.6-py3-none-any.whl 4.7 kB Oct 25, 2018	Python 3	none	any	Details

Total release size: 9.6 kB

Release files / dicteval-0.0.6.tar.gz

Download URL	dicteval-0.0.6.tar.gz
Size	4.9 kB
Tags	Source
SHA-256 checksum How to use checksums	`20ab0af2ac567f970ed82aadd9fcdbb63695a18be4cda112029b0fc4d1ed6933`
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Upload date	Oct 25, 2018
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Uploaded via	`twine/1.12.1 pkginfo/1.4.2 requests/2.20.0 setuptools/40.4.3 requests-toolbelt/0.8.0 tqdm/4.28.1 CPython/3.7.0`

Release files / dicteval-0.0.6-py3-none-any.whl

Download URL	dicteval-0.0.6-py3-none-any.whl
Size	4.7 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`8172c80b3ed259d18d4c622bb45b8a9e5fcc67845135e01619f415efb98ae87d`
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Upload date	Oct 25, 2018
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/1.12.1 pkginfo/1.4.2 requests/2.20.0 setuptools/40.4.3 requests-toolbelt/0.8.0 tqdm/4.28.1 CPython/3.7.0`