Home » Python » Python Reference » Python Built-in Functions

Python float() Function: Use, Syntax, and Examples

By IncludeHelp Last updated : December 07, 2024

Python float() function

The float() function is a library function in Python, it is used to get a float value from a given number or a string. It accepts either a string (that should contain a number) or a number and returns a float value.

Consider the below example with sample input/output values:

Input:
val1 = "10.23"
val2 = "10"
val3 = 10
print(float(val1))
print(float(val2))
print(float(val3))
    
Output:
10.23
10.0
10.0

Syntax

The following is the syntax of float() function:

float(value)

Parameter(s):

The following are the parameter(s):

• value – string or number to be converted into float.

Return Value

The return type of float() function is <type 'float'>, it returns a float value.

Python float() Example 1: String and integer to float

# python code to demonstrate an example
# of float() function

print(float("10.23"))   # will return 10.23
print(float("10"))      # will return 10.0
print(float(10))        # will return 10.0
print(float(10.23))     # will return 10.23

Output

10.23
10.0
10.0
10.23

Python float() Example 2: Input a float value

# Input float value 

# Input
height = float(input("Enter height: "))

# Print 
print("height:", height)

Output

Enter height: 160.5
height: 160.5

Python float() Example 3: ValueError

If the given value is not a valid float or integer, the function returns a ValueError.

float# ValueError

x = float("weight 160.5") # ValueError 
print(x)

Output

Traceback (most recent call last):
  File "/home/main.py", line 3, in <module>
    x = float("weight 160.5") # ValueError 
ValueError: could not convert string to float: 'weight 160.5'