all Python 3Exceptionsexception

AttributeError

built-in exceptions

Raised when an attribute or method that the object does not have is accessed.

Syntax

raise AttributeError('сообщение')

Most student AttributeErrors are really None in disguise: in-place methods such as list.sort(), list.append() and random.shuffle() return None, so after lst = lst.sort() the very next call dies with "'NoneType' object has no attribute ...". Read the message to the end — it names both the object's type and the attribute, and since 3.10 the interpreter also suggests a close match when you merely mistyped.

Examples

x = 42
x.upper()            # AttributeError: 'int' has no 'upper'

class A: pass
A().run()            # AttributeError

See also

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