CODEWITHSUNDEEP
pythonclassattributes
theta
theta

Reputation: 135

How to create class from which I can use "get"?

In Python, I am trying to create a class that has attributes which I can "get" (sorry if this wording is not exactly correct).

Basically I am trying to define some class p which has attributes var1 and var2. So then I can use p.get("var1") and p.get("var2") to get the values of these respective attributes. How can I define something like this?

Upvotes: 0

Views: 680

Answers (2)

Harun Yilmaz
Harun Yilmaz

Reputation: 8558

You can define a class with get() method and check if the instance has the attribute with built-in getattr() method as following:

class MyClass:

  def get(self, property, default=None):
    return getattr(self, property, default)

  var1 = 'var1'
  var2 = 'var2'


myInstance = MyClass()

print(myInstance.get('var1'))
print(myInstance.get('var3', 'NonExisting Attribute'))

Here's a working repl.it project that I just created: https://repl.it/@HarunYlmaz/OvalLiveMethod

You can also check if the instance has the attribute with hasattr() method:

class MyClass:

  def get(self, property, default=None):
    if hasattr(self, property):
      return getattr(self, property)
    else:
      return default
      # Or you can raise an exception here

Upvotes: 1

K. Prot
K. Prot

Reputation: 169

For instance object

class Test:
    
    def __init__(self):
        self.a = 1
        self.b = 2
    
    def get(self, var):
        return eval('self.%s' % var)
    
t = Test()
a = t.get('a')
print(a) ## output: 1

For class object

class Test:
    
    a = 1
    b = 2
    
    @classmethod
    def get(cls, var):
        return eval('cls.%s' % var)
    
a = Test.get('a')
print(a) # output: 1

Upvotes: 0

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