Skip to main content

How to Resolve Python "AttributeError: 'float' object has no attribute '...'"

The AttributeError: 'float' object has no attribute '...' error in Python indicates you're trying to use an attribute or method on a floating-point number (a number with a decimal, like 3.14 or 10.0) that doesn't actually exist for that data type. Floats primarily support numerical operations and have a limited set of built-in attributes compared to more complex types like strings or custom objects.

This guide explains the common causes of this error, focusing on incorrect method calls like .split() or .round(), and provides solutions.

Understanding Python Floats (float)​

Floats in Python represent real numbers (numbers with potential decimal components). They are primarily designed for mathematical calculations. They have a specific, relatively small set of built-in methods mostly related to their numerical nature (like is_integer(), as_integer_ratio(), hex()) but lack methods found on other types:

  • They don't have string manipulation methods (.split(), .upper(), .strip(), etc.).
  • They don't have list methods (.append(), .sort(), etc.).
  • They don't have dictionary methods (.keys(), .items(), etc.).
  • They don't typically have methods named after common built-in functions like round.

The Cause: Type Mismatch - Accessing Non-Existent Attributes​

This AttributeError occurs because your code attempts to perform an operation like my_float.some_attribute or my_float.some_method() where my_float holds a floating-point number, but the specified attribute or method (some_attribute or some_method) is not defined for the float type. The variable contains a different type than the operation expects.

Scenario 1: Using String Methods on a Float (e.g., .split())​

A common mistake is trying to use string methods directly on a float, perhaps intending to work with its string representation.

Cause and Error Example​

You cannot call string methods like .split() directly on a float object.

value = 123.45

print(f"Type of value: {type(value)}") # Output: Type of value: <class 'float'>

try:
    # ⛔️ AttributeError: 'float' object has no attribute 'split'
    # .split() is a string method, not available for floats.
    parts = value.split('.')
    print(parts)
except AttributeError as e:
    print(e)

Solution: Convert Float to String (str())​

If you need to perform string operations (like splitting on the decimal point), first explicitly convert the float to its string representation using the str() function.

value = 123.45

# ✅ Convert the float to a string first
value_str = str(value)
print(f"String representation: '{value_str}', Type: {type(value_str)}")
# Output: String representation: '123.45', Type: <class 'str'>

# ✅ Now call .split() on the string
parts = value_str.split('.')
print(f"Split parts: {parts}")
# Output: Split parts: ['123', '45']

Output:

String representation: '123.45', Type: <class 'str'>
Split parts: ['123', '45']
note

This applies to any string method (e.g., str(value).startswith('123'), str(value).replace('.', ',')).

Scenario 2: Confusing Built-in Functions with Methods (e.g., round())​

Another frequent error is attempting to call a built-in function as if it were a method of the float object. round() is a prime example.

Cause and Error Example​

round() is a built-in function in Python, not a method attached to float objects. You pass the float to the function, you don't call the function on the float using dot notation.

value = 7.89

print(f"Type of value: {type(value)}") # Output: Type: <class 'float'>

try:
    # ⛔️ AttributeError: 'float' object has no attribute 'round'
    # Trying to call round() as if it were a method of the float.
    rounded_value = value.round()
    print(rounded_value)
except AttributeError as e:
    print(e)

Output:

Type of value: <class 'float'>
'float' object has no attribute 'round'

Solution: Use the Built-in round() Function Correctly​

Pass the float variable as an argument to the round() function.

value = 7.89

# ✅ Correct: Pass the float TO the round() function
rounded_value_int = round(value) # Rounds to nearest integer
print(f"Rounded to nearest int: {rounded_value_int}")       # Output: Rounded to nearest int: 8

# ✅ Correct: Round to a specific number of decimal places
rounded_value_1dp = round(value, 1) # Rounds to 1 decimal place
print(f"Rounded to 1 decimal place: {rounded_value_1dp}")   # Output: Rounded to 1 decimal place: 7.9

Output:

Rounded to nearest int: 8
Rounded to 1 decimal place: 7.9
note

Remember the signature of round(): round(number, ndigits=None).

Debugging Steps​

Check the Variable's Type (type())​

Confirm the variable holds a float right before the error:

print(f"DEBUG: Type of my_variable is {type(my_variable)}")
# >> The line causing the error, e.g., result = my_variable.attribute

If it prints <class 'float'>, the variable type is confirmed.

Check Available Float Attributes/Methods (dir())​

See what's actually defined for floats:

value = 3.14
print(dir(value))

Output:

['__abs__', '__add__', '__bool__', '__class__', '__delattr__', '__dir__', '__divmod__', '__doc__', '__eq__', '__float__', '__floordiv__', '__format__', '__ge__', '__getattribute__', '__getformat__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__int__', '__le__', '__lt__', '__mod__', '__mul__', '__ne__', '__neg__', '__new__', '__pos__', '__pow__', '__radd__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rmod__', '__rmul__', '__round__', '__rpow__', '__rsub__', '__rtruediv__', '__set_format__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', 'as_integer_ratio', 'conjugate', 'fromhex', 'hex', 'imag', 'is_integer', 'real']
note

Notice the absence of 'split', 'round', 'upper', 'append', etc.

note

If the attribute/method you're trying isn't in this list, it won't work on a float.

Trace Variable Assignment​

If you didn't expect the variable to be a float at that point, investigate:

  • Where was it last assigned?
  • Did a calculation (like division /) result in a float?
  • Did a function return a float unexpectedly?
  • Was it accidentally reassigned?

General Solutions Review​

When faced with AttributeError: 'float' object has no attribute:

  • Correct the Variable Type/Assignment: If the variable shouldn't be a float at that point, fix the preceding logic or assignment that caused it to become one.
  • Convert Type When Necessary: If you need string-like operations, convert the float using str(my_float) before applying string methods.
  • Use Built-in Functions Correctly: For operations like rounding, use the appropriate built-in function (e.g., round(my_float)) instead of trying to call it as a method (my_float.round()).
  • Defensive Check: Using hasattr() (Use with Caution): You can check if hasattr(my_float, 'attribute_name'): before access. However, this usually masks the real problem (variable holding the wrong type or misunderstanding float capabilities) rather than fixing it. Only use it if you genuinely expect the variable might hold different types with varying attributes.

Conclusion​

The AttributeError: 'float' object has no attribute '...' arises because floating-point numbers in Python have a limited set of primarily numeric methods and attributes. You cannot directly call methods belonging to other types (like strings) or mistake built-in functions (like round()) for methods on floats.

The solutions involve:

  1. Ensuring the variable holds the correct type you expect for the operation.
  2. Explicitly converting the float to another type (e.g., str()) if you need to perform operations specific to that type.
  3. Using built-in functions correctly by passing the float as an argument, not calling the function as a method.

By understanding the capabilities of the float type and using type conversion or built-in functions appropriately, you can easily resolve these attribute errors.

Table of Contents