Why does an error 'Property does not exist' when calling a property in a Python class?

This article analyzes the AttributeError problem caused by class attribute call error in Python 3.12. The problem stems from a simple spelling error that causes the class attribute to be unable to be initialized correctly.

Question description:

The code throws AttributeError when calling the attribute defined in the __init__ method, prompting that the attribute does not exist.

Error code:

 class getconfig(object):
    def __int__(self): # Error spelling: __int__ instead of __init__
        current_dir = os.path.dirname(os.path.abspath(__file__))
        print(current_dir)
        sys_cfg_file = os.path.join(current_dir, "sysconfig.cfg")
        self.conf = configparser.configparser()
        self.conf.read(sys_cfg_file)

    def get_db_host(self):
        db_host = self.conf.get("db", "host")
        return db_host

if __name__ == "__main__":
    gc1 = getconfig()
    var = gc1.get_db_host()

error message:

 <code>AttributeError: 'getconfig' object has no attribute 'conf'</code>

Error analysis:

The __int__ method is not a constructor in Python, the correct constructor name is __init__ . Due to a typo, the __init__ method is not called, so the self.conf property is not initialized, causing the get_db_host method to try to access the non-existent property conf .

Solution:

Correct __int__ to __init__ and recommend a more standardized naming method (such as capitalization of the initials):

 import os
import configparser # Make sure the configparser module is imported class GetConfig(object):
    def __init__(self):
        current_dir = os.path.dirname(os.path.abspath(__file__))
        print(current_dir)
        sys_cfg_file = os.path.join(current_dir, "sysConfig.cfg") #It is recommended that file names also use the consistent naming specifications self.conf = configparser.ConfigParser()
        self.conf.read(sys_cfg_file)

    def get_db_host(self):
        db_host = self.conf.get("DB", "host") # It is recommended to use uppercase "DB" to maintain consistency return db_host

if __name__ == "__main__":
    gc1 = GetConfig()
    var = gc1.get_db_host()
    print(var) # Print the result and verify whether it is successful

With this simple correction, the code will run normally and successfully access conf property. Remember that Python is case sensitive and following consistent naming specifications is critical to the readability and maintainability of your code.

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