Imperium

Imperium is a python package that allows you to easily evaluate python expressions

Installation

pip install imperium

Usage

from imperium import Expression

obj = {
    'name': 'iPhone',
    'model': '11 Pro',
    'price': 1299.90,
    'state': 'new'
}

expr = Expression()
if expr.evaluate('$subject.state == "new"', obj): # "$subject" is a reserved key
    # Your logic

To access the data in the given subject, use the "$subject" key as shown above.

Check if the subject has an attribute

from imperium import Expression

obj = {
    'name': 'iPhone',
    'model': '11 Pro',
    'price': 1299.90,
    'state': 'new'
}

someother_obj = {
    'name': 'John Doe'
}

expr = Expression()
res = expr.evaluate('exists("$subject.price", $subject)', subject=obj, source=someother_obj) # REMINDER: "$subject" key let's you access the object that you passed to the evaluate method (obj in this case)
print(res) # Output: True

Testing regular expressions

from imperium.evaluator import Expression

obj = {
    'name': 'iPhone',
    'model': '11 Pro',
    'price': 1299.90,
    'state': 'new'
}

buyer = {
    'fullname': 'John Doe'
}

# Passing the name attribute of the subject
# REMINDER: "$subject" let's you access the object/subject passed to the evaluate method (obj in this case)
# and "$source" let's you access the optional source object passed to the evaluate method 

# INFO: "matches" function let's you evaluate a regular expression against a value, note that the supported flag are "i" and "m"
# if you use something else than these two flags, the evaluation will procede by ignoring the flag since it didn't recognize it.

expression = "exists('$subject.name', $subject) && matches('IPHONE', $subject['name'], 'i')"

expr = Expression()
res = expr.evaluate(expression, subject=obj, source=buyer)
print(res) # Output: True

Imperium has built-in functions to simplify certain actions/verifications.