How to handle object null in python

Question

I am using flask. When I do not pass StartingSequenceNumber to flask app then How can I handle null object.

  class Meta():


    def __init__(self, j):
        self.__dict__ = json.loads(j)

in bootstrap.py

   meta = Meta(request.get_data().decode())
   if meta.StartingSequenceNumber is not None:
     # do something

Error : AttributeError: 'Meta' object has no attribute 'StartingSequenceNumber'

https://stackoverflow.com/questions/610883/how-to-know-if-an-object-has-an-attribute-in-python are you looking for something like this? — Aditya, Jan 15 '18 at 12:59

score 0 · Accepted Answer · answered Jan 15 '18 at 13:23

You could use the hasattr() built-in function (https://docs.python.org/3/library/functions.html#hasattr) which will return True if the object has the attribute :

if hasattr(object, 'attribute'): 
    # do smthg
else:
    # do smthg else

But it would be better to used try & except blocks and throw an AttributeError

try:
    doSmthg()
except AttributeError:
    # do smthg else

1 Answers1