AttributeError – invalid attribute reference

AttributeError can be defined as an error raised when an attribute reference or assignment fails.

Example 1

This code tries to append to a string object.

The code first creates a string object str with the value “Test”. Then, it calls the append method on this string object, which is not valid as strings are immutable in Python, and cannot be modified. This operation would result in an AttributeError.

To handle such exceptions, the code uses a try-except block to catch the error. In case an AttributeError is raised, the code inside the except block will be executed.

The code inside the except block first prints the message “AttributeError occurred:” and then prints the error message contained in the exception object e using print(e).

The try-except block allows the code to continue executing even in the presence of errors, without crashing the program. It provides a way to handle exceptions and provides a more user-friendly output.

try:
    str = "Test"
    str.append()
except AttributeError as e:
    print("AttributeError occurred: ")
    print(e)

Output

AttributeError occurred: 
'str' object has no attribute 'append'

Example 2

This code defines a Person class with an __init__ method that initializes two attributes prename and name to “John” and “White” respectively.

The code then creates an instance of the Person class, and tries to access and print the values of the prename and name attributes. It then tries to access the value of an undefined attribute age on the Person instance p.

Since the attribute age is not defined for the Person class, accessing it would result in an AttributeError.

To handle such exceptions, the code uses a try-except block to catch the error. In case an AttributeError is raised, the code inside the except block will be executed.

The code inside the except block first prints the message “AttributeError occurred:” and then prints the error message contained in the exception object e using print(e).

The try-except block allows the code to continue executing even in the presence of errors, without crashing the program. It provides a way to handle exceptions and provides a more user-friendly output.

class Person:
    def __init__(self):
        self.prename = "John"
        self.name = "White"


try:
    p = Person()
    print(p.prename + " " + p.name)
    print(p.age)
except AttributeError as e:
    print("AttributeError occurred: ")
    print(e)

Output

AttributeError occurred: 
'Person' object has no attribute 'age'