The TypeError: vars() argument must have __dict__ attribute error occurs when you try to “call the built-in vars() function on an object that doesn’t have a __dict__ attribute”.
The vars() function is used to get an object’s __dict__ attribute, which contains its attributes in the form of a dictionary.
To fix this error, check if the object has a __dict__ attribute before calling vars() or using the dir() function.
Method 1: Check if the object has a __dict__attribute
Check if the object has a __dict__ attribute before calling the vars() function.
Example
class MyClass:
pass
class MyClassWithoutDict:
__slots__ = []
obj1 = MyClass()
obj2 = MyClassWithoutDict()
if hasattr(obj1, '__dict__'):
print(vars(obj1))
else:
print("obj1 doesn't have a __dict__ attribute")
if hasattr(obj2, '__dict__'):
print(vars(obj2))
else:
print("obj2 doesn't have a __dict__ attribute")
Output
{}
obj2 doesn't have a __dict__ attribute
Method 2: Using the dir() function
Use the dir() function to get all object attributes, including its class attribute.
class MyClass:
pass
class MyClassWithoutDict:
__slots__ = []
obj1 = MyClass()
obj2 = MyClassWithoutDict()
print("Attributes of obj1:")
for attribute in dir(obj1):
print(f"{attribute}: {getattr(obj1, attribute)}")
print("\nAttributes of obj2:")
for attribute in dir(obj2):
print(f"{attribute}: {getattr(obj2, attribute)}")Output
In this code, we used the dir() function to get all object attributes, including its class attributes.
Remember that dir() will not give you the same output as vars(), as it lists all attributes, not just the instance attributes stored in the object’s __dict__.
