How to Fix: AttributeError: ‘int’ object has no attribute ‘x’

This is a fundamental AttributeError that means: “You are trying to use a method (like .append() or .lower()) on a simple number (an integer).” This is commonly referred to as the AttributeError int object error in Python programming.

An “attribute” or “method” is something you access with a dot (.). Integers have very few of these.

The Cause

You have a variable that you think is a list or a string, but it’s actually just a number.

Problem Code 1 (Confusing a list with an int):

my_list = [1, 2, 3]

# This is fine:
print(len(my_list)) # Output: 3

# This is a mistake:
my_count = len(my_list) # my_count is the NUMBER 3

my_count.append(4)
# CRASH! AttributeError: 'int' object (the number 3) has no attribute 'append'

Problem Code 2 (Confusing a string with an int):

my_var = 123
print(my_var.lower())
# CRASH! AttributeError: 'int' object has no attribute 'lower'

The .lower() method only exists for strings.

The Fix

The fix is to find where you incorrectly assigned your variable.

• If you meant to add to my_list, you should have just done my_list.append(4).
• If you meant to use .lower(), you must first convert your number to a string: str(my_var).lower().

This error always means you have the wrong data type for the method you are trying to use.