Initialize object type to corresponding empty value in python

Question

I have a class that contains a dictionary of properties current_properties, the properties that can be added and their corresponding data types are predefined in valid_properties dictionary:

self.valid_properties = {'name': str, 'number': int, 'point_data': list}
self.current_properties = {'name': 'user_1'}

Now, I want to write a method that initializes every new added property to its corresponding empty value. e.g. number is int, once added, new state should be:

self.current_properties = {'name': 'user_1', 'number': 0}

if I add point_data the new state should be:

self.current_properties = {'name': 'user_1', 'number': 0, 'point_data':[]}

How can I get this done?

"every new added property" - how do you "add" new properties? — Jundiaius
– Jundiaius, Commented Jun 25, 2018 at 12:25

Cory Kramer · Accepted Answer · 2018-06-25 12:27:48Z

4

You can look up the type from valid_properties using whatever key you want to insert, then use () to instantiate an object of that type.

>>> valid_properties = {'name': str, 'number': int, 'point_data': list}
>>> current_properties = {'name': 'user_1'}
>>> current_properties
{'name': 'user_1'}
>>> current_properties['number'] = valid_properties['number']()
>>> current_properties
{'number': 0, 'name': 'user_1'}

answered Jun 25, 2018 at 12:27

Cory Kramer

119k19 gold badges176 silver badges233 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Austin · Accepted Answer · 2018-06-25 12:37:25Z

Use:

valid_properties = {'name': str, 'number': int, 'point_data': list}
current_properties = {'name': 'user_1'}

current_properties['number'] = valid_properties['number']()
current_properties['point_data'] = valid_properties['point_data']()

print(current_properties)
# {'name': 'user_1', 'number': 0, 'point_data': []}

How?

>>> k = int()                                               
>>> k                                                       
0                                                           
>>> k = list()                                              
>>> k                                                       
[]

int():

Takes number or string to be converted to integer object, and base of the number as parameters. If no parameters are passed, returns 0.

list():

Takes an iterator as parameter. If no parameters are passed, it creates an empty list.

Collectives™ on Stack Overflow

Initialize object type to corresponding empty value in python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related