Why Does My Python Class Constructor Fail with `TypeError: Example() takes no arguments` or `AttributeError`?

Confusion with Class Constructor Naming:

During class construction, new Python programmers often encounter errors related to misnamed class constructors. Two common typos are using "def __int__" instead of "def __init__" or "def _init_" instead of "def __init__."

"def __int__":

The class constructor should be named "__init__" with two underscores on each side. Using "def __int__" assigns the integer conversion function to the class, resulting in errors when attempting to instantiate the class with arguments.

class Example:
    def __int__(self, parameter):  # Incorrect
        self.attribute = parameter

"def _init_":

Using "def _init_" also leads to errors because it does not match the expected constructor name.

class Example:
    def _init_(self, parameter):  # Incorrect
        self.attribute = parameter

"TypeError: Example() takes no arguments":

When trying to create an instance of the class, the error "TypeError: Example() takes no arguments" occurs because the incorrect constructor name has assigned the integer conversion function.

"AttributeError: 'Example' object has no attribute 'attribute'":

This error indicates that the class instance does not have the expected attribute. The reason for this is that the incorrect constructor name has not set the attribute within the class.

Prevention:

To avoid these errors, always ensure that the class constructor is named correctly as "__init__". Proofreading and training are essential for catching these typos. Additionally, having the convention of placing "__init__" as the first method in the class can help prevent errors.

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