AttributeError

AttributeError is raised when you try to access an attribute or method that doesn't exist on an object. This includes calling methods on the wrong type or accessing misspelled attribute names.

Common causes

• Calling a method on the wrong type (e.g., .append() on a string)
• Typo in attribute or method name
• Accessing an attribute on None
• Object missing expected attribute due to incomplete initialization
• Using a module attribute that was removed or renamed

How to fix it

• Use hasattr() to check if an attribute exists before accessing it
• Use getattr() with a default value: getattr(obj, "attr", default)
• Check the type of the object with type() or isinstance()
• Verify the object is not None before accessing attributes
• Use dir(obj) to see available attributes

Example

# Error example
name = "Alice"
name.append(" Smith")
# AttributeError: 'str' object has no attribute 'append'

result = None
result.process()
# AttributeError: 'NoneType' object has no attribute 'process'

# Fix: use correct method for type
name = "Alice"
name = name + " Smith"  # or f"{name} Smith"

# Fix: check for None
if result is not None:
    result.process()

# Fix: use getattr with default
value = getattr(obj, "missing_attr", "default_value")

Related errors