How to Fix Python ValueError: Invalid Literal for Float()

1. the ValueError: invalid literal for float() in Python
2. Fix the ValueError: invalid literal for float() in Python

When you pass an unrecognized argument that isn’t supported by the float() function, the Python compiler will arise an error such as ValueError: invalid literal for float(). The python compiler arises this ValueError: invalid literal for float() in Python 2x versions and ValueError: could not convert string to float in Python 3x versions when you pass the string value as an argument to the float() function.

the ValueError: invalid literal for float() in Python

The float() function isn’t capable of typecasting a string into a floating point number. Rather it throws a ValueError which can be different depending on your Python version.

Let’s see an example for both Python 2 and Python 3.

Code - Python 2:

# python 2.7
import sys

print("The Current version of Python:", sys.version)

x = "123xyx"
y = float(x)
print(y)

Output:

The current version of Python: 2.7.18
ValueError: invalid literal for float(): 123xyx

Code - Python 3:

# >= Python 3.7
import sys

print("The Current version of Python:", sys.version)

x = "123xyx"
y = float(x)
print(y)

Output:

The current version of Python: 3.7.4
ValueError: could not convert string to float: '123xyx'

We ran the same code in Python 2.7 and Python 3.7, but the error isn’t the same because of improvement and continuous development of Python’s compiler.

Fix the ValueError: invalid literal for float() in Python

To fix the value error invalid literal for float() or could not convert string to float, you need to provide a valid literal as an argument to the float() function so it can parse it correctly.

You can provide a valid numeric string (only digits) or an integer value to the float function to work perfectly.

Code:

h = input("Enter you height:")
print(type(h))

height = float(h)
print("\nYour height is:", height)
print(type(height))

Output:

Enter you height:5.4
<class 'str'>

Your height is: 5.4
<class 'float'>

The value of height is always in float, but the input statement takes every input as a string. So, in the above case, the user entered their height "5.4" whose class is str, but later we have type cast it to 'float'.