In this article, you will learn what the Python error TypeError: can't multiply sequence by non-int of type float
means.
Firstly, I will explain why this error gets raised. You will also learn how to solve the error and how to avoid it in the first place.
Here is what we will cover:
- What is the
TypeError: can't multiply sequence by non-int of type float
error in Python? - How to solve the
TypeError: can't multiply sequence by non-int of type float
error in Python
What Is The TypeError: can't multiply sequence by non-int of type float
Error in Python?
There are two types of numbers in Python:
- integers – whole numbers that can be positive, negative, or zero.
- floating-point numbers – positive or negative numbers with a decimal point.
You can multiply an integer with a string to create a repeating sequence of characters:
print("Python" * 3)
# output
# PythonPythonPython
And as a reminder, strings are any characters enclosed in single or double quotation marks – including numbers:
print("3" * 3)
# output
# 333
But look at what happens when you try to multiply a string with a floating-point number:
print("3" * 3.3)
# output
# Traceback (most recent call last):
# File "main.py", line 1, in <module>
# print("3" * 3.3)
# TypeError: can't multiply sequence by non-int of type 'float'
An error gets raised – specifically a TypeError
.
A TypeError
is an exception in Python that gets raised when you try to operate on a data type that doesn't support that specific operation.
As the error message lets you know, you cannot perform multiplication between a string (or sequence) and a floating point number (or float), as Python doesn't support that operation between those two data types.
How Does The TypeError: can't multiply sequence by non-int of type float
Error Occur in Python?
The TypeError: can't multiply sequence by non-int of type float
error commonly occurs when you use the Python input()
function, which takes user input. This is because, by default, the input()
function returns the user input as a string.
Let's take the following hypothetical example. Say that I ask a user to enter their age and store their answer in a variable with the name user_age
:
user_age = input("Please enter your age: ")
I can check the data type of the value stored in the variable user_age
by using the type()
function and then print the result to the console:
user_age = input("Please enter your age: ")
print(type(user_age))
# output
# Please enter your age: 29
# <class 'str'>
From the output, you can see that even though I entered an integer, the return data type is of type string.
If I then, for whatever reason, wanted to multiply the user's age with a floating-point number, I would get the TypeError: can't multiply sequence by non-int of type float
error:
user_age = input("Please enter your age: ")
print(user_age * 0.5)
# output
# Please enter your age: 29
# Traceback (most recent call last):
# File "main.py", line 3, in <module>
# print(user_age * 0.5)
# TypeError: can't multiply sequence by non-int of type 'float'
How To Solve The TypeError: can't multiply sequence by non-int of type float
Error in Python
To solve the TypeError: can't multiply sequence by non-int of type float
error, convert the string into a floating-point number before multiplying it with a float.
As you saw earlier on, the following throws the TypeError: can't multiply sequence by non-int of type float
error:
print("3" * 3.3)
# output
# Traceback (most recent call last):
# File "main.py", line 1, in <module>
# print("3" * 3.3)
# TypeError: can't multiply sequence by non-int of type 'float'
If you convert the string "3"
to a float before multiplying it with the floating-point number 3.3
, there will be no error.
To convert a string to a float, use the float()
function:
print(float("3") * 3.3)
# output
# 9.899999999999999
And you can do the same when you use the input()
function. Convert the value the user enters to a floating-point number using the float()
function.
Here is how you would re-write the example using the input()
function from earlier on:
user_age = float(input("Please enter your age: "))
print(user_age * 0.5)
# output
# Please enter your age: 29
# 14.5
The float()
function converts the string value returned by the input()
function into a floating-point number, and you can multiply that value with a floating-point number.
Conclusion
And there you have it! You now know how to solve the TypeError: can't multiply sequence by non-int of type float
error in Python!
I hope you found this tutorial helpful.
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Thank you for reading, and happy coding!