Floats and iterables are distinct objects In Python. A float is any decimal point number, and an iterable is an object capable of returning elements one at a time, for example, a list. A float is a single value and does not contain other values. If you try to iterate over a float, you will raise the error “TypeError: ‘float’ object is not iterable“.
To solve this error, ensure you use the range() method, for example,
for number in range(floating_point_number)
to iterate over a range of numbers up to the specified floating_point_number.
This tutorial will go through the error in detail. We will go through two example scenarios and learn how to solve them.
Table of contents
TypeError: ‘float’ object not iterable
What is a TypeError?
A TypeError occurs when we try to perform an operation on the wrong type of object. For example, if we try to calculate the square root of a list instead of an integer or a floating-point number, then a TypeError will be generated by the Python interpreter.
Difference Between a Float and an Iterable
Iterables are containers that can store multiple values and return them one by one. Iterables can store any number of values, and the values can either be the same type or different types. You can go to the next item in an iterable object using the next() method.
A floating-point number is any number with a decimal point. You can define a floating-point number in Python by defining a variable and assigning a decimal point number to it.
x = 4.2 print(type(x))
class 'float'
Floating-point numbers do not store multiple values like a list or a dictionary. If you try to iterate over a float, you will raise the error “TypeError: ‘float’ object is not iterable” because float does not support iteration.
You will get a similar error if you try to iterate over an integer or a NoneType object.
Example #1: Iterate Over a Floating Point Number
Let’s look at an example where we initialize a floating-point number and iterate over it.
# Define floating point number
float_num = 10.0
# Iterate over the floating point number
for num in float_num:
print(num)
Let’s see what happens when we run the code:
TypeError Traceback (most recent call last)
1 for num in float_num:
2 print(num)
3
TypeError: 'float' object is not iterable
We raise the error because Python does not support iteration on a floating-point number.
Solution #1: Convert float to string Using the str() Method
The first solution involves converting the float_num object to a string using the str() method and iterating over every digit. We can do iteration over a string because the string type is iterable. However, the for loop will return each character of the float_num string.
# Define floating point number
float_num = 10.0
# Iterate over the floating point number
for digit in str(float_num):
print(digit)
Solution #2: Iterate Using the range() Method
To print the range of numbers, we can use the int() method to convert the number to an integer and then use the integer as input to the range() method. The range() method only accepts integer numbers, in which case we have to convert any floating-point number that we want to iterate over to an integer. The range() method returns an iterable object which we can iterate over using a for loop.
# Define floating point number
float_num = 30.0
# Convert the float number to an integer
int_num = int(float_num)
# Iterate over the floating point number
for num in range(int_num):
print(num)
Let’s see what happens when we run the revised code:
0 1 2 3 4 5 6 7 8 9
Example #2: Determine if a Number is Prime
Let’s look at another example where we write a program to check if a number entered by the user is prime or not. Prime numbers are only divisible by themselves, and 1. To start, we will ask the user to insert the number to determine whether it is prime or not.
number = float(input("Enter a number: "))
Then we define a function that determines whether the number is prime by using the modulo operator %. If the remained of x % y equals zero, then y is a factor of x. Prime numbers have two factors, one and itself.
# Function to determine if number is prime or not
def prime_number_calc(num):
for i in num:
# Ensure we do not divide the number by zero or one
if i > 1:
if num % i == 0:
print(f'{num} is not prime')
break
# If the loop runs completely the number is prime
else:
print(f'{num} is a prime number')
prime_number_calc(number)
Let’s run the code to see what happens:
TypeError Traceback (most recent call last)
1 def prime_number_calc(num):
2 for i in num:
3 if i > 1:
4 if num % i == 0:
5 print(f'{num} is not prime')
TypeError: 'float' object is not iterable
The Python interpreter throws the TypeError because a floating-point number is not a suitable type to iterate over. A for loop requires an iterable object to loop over.
Solution
To solve this problem, we need to convert the input number to an integer using int() and pass the integer the range() method instead of the float. Let’s look at the revised code:
def prime_number_calc(num):
for i in range(int(num)):
if i > 1:
if num % i == 0:
print(f'{num} is not prime')
break
else:
print(f'{num} is a prime number')
number = float(input("Enter a number: "))
prime_number_calc(number)
Let’s run the code to see what happens:
Enter a number: 17.0 17.0 is a prime number
Our code successfully prints the result that 17.0 is a prime number.
Summary
Congratulations on reading to the end of this tutorial. The error “TypeError: ‘float’ object is not iterable” occurs when you try to iterate over a floating-point number as if it were an iterable object like a list.
You must use the range() method to iterate over a collection of numbers. However, you must convert the float to an integer beforehand passing it to the range() method. If you want to iterate over the digits of the float, you can convert the float to a string and use the range() function.
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