To fix the TypeError: Unsupported operand type(s) for *: float and decimal.Decimal in Python. I will do the object conversion, use the Decimal module and check the object type. Post details below.
What causes the TypeError: Unsupported operand type(s) for *: float and decimal.Decimal?
The error happens when you multiply a float object by a decimal object.
Example:
from decimal import Decimal
valueFloat = 1.2
decimalObj = Decimal('1.2')
print(valueFloat * decimalObj)Output:
Traceback (most recent call last):
File "./prog.py", line 5, in <module>
TypeError: unsupported operand type(s) for *: 'float' and 'decimal.Decimal'How to solve this error?
Converting float to decimal
To avoid the error, all you need to do is converting the float object to a decimal number.
Example:
- Converting float to the decimal object using the Decimal() function.
- Multiplying 2 decimal objects will not throw an error.
from decimal import Decimal
valueFloat = 1.2
# Float object converts to decimal.
valueFloat = Decimal(valueFloat)
decimalVar = Decimal(1.2)
print('Multiplication result:', valueFloat * decimalVar)Output:
Multiplication result: 1.439999999999999893418589636Or you can convert Decimal objects to floats using the float() function and multiply them together.
Example:
from decimal import Decimal
valueFloat = 1.2
decimalVar = Decimal(1.2)
# Decimal object converts to float.
decimalVar = float(decimalVar)
print('Multiplication result:', valueFloat * decimalVar)Output:
Multiplication result: 1.44Using the Decimal Module
Example:
- Import the Decimal module.
- Implement the decimal object using the Decimal() function from the Decimal module.
- Perform rounding to 2 digits after the decimal point using the getcontext() function.
from decimal import Decimal, getcontext
firstDecimalFactor = Decimal(1.2)
secondDecimalFactor = Decimal(2.4)
# The getcontext() function rounds the math.
# Get 2 numbers after the decimal point.
getcontext().prec = 2
print('Multiplication result:', firstDecimalFactor * secondDecimalFactor)Output:
Multiplication result: 2.9When you enclose numbers in single quotes, the results are automatically rounded.
Example:
from decimal import Decimal
firstDecimalFactor = Decimal('1.2')
secondDecimalFactor = Decimal('2.4')
print('Multiplication result:', firstDecimalFactor * secondDecimalFactor)Output:
Multiplication result: 2.88Checking the decimal object
To check if an object is a decimal object, use the isinstance() function or the type() function.
Example:
from decimal import Decimal
firstDecimalFactor = Decimal('1.2')
# Use the isinstance() function to check.
print('Here is the decimal object:', isinstance(firstDecimalFactor, Decimal))
# Use the type() function to check.
print('What object is this?', type(firstDecimalFactor))Output:
Here is the decimal object: True
What object is this? <class 'decimal.Decimal'>Summary
The topic TypeError: Unsupported operand type(s) for *: float and decimal.Decimal done. You can use the Decimal module to solve this problem. It is pretty convenient. If you have any comments on the article, please leave a comment below.
Maybe you are interested:
- TypeError: unsupported operand type(s) for -: str and int
- TypeError: unsupported operand type(s) for +: ‘NoneType’ and ‘str’
My name is Jason Wilson, you can call me Jason. My major is information technology, and I am proficient in C++, Python, and Java. I hope my writings are useful to you while you study programming languages.
Name of the university: HHAU
Major: IT
Programming Languages: C++, Python, Java
