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Parse a string to float in Python (float() function)
Python float() function example: Here, we are going to learn how to convert a given string value to the float value in Python?
By IncludeHelp Last updated : December 17, 2023
Prerequisites
To understand this example, you should know the following Python topics:
Problem statement
Given a string value (that contains float value) and we have to convert it into float value in Python.
Example:
Input:
str = "10.23"
print(float(str))
Output:
10.23
Input:
str = "1001"
print(float(str))
Output:
1001.0
Parsing a string to a float value
To parse a string value to a float value in Python, use the float() method, which is a library function in python, it is used to convert a given string or integer value to the float value.
Below is the syntax of float() method:
float(string_value/integer_value)
Python program to parse a string to a float value
# python code to demonstrate example of
# float() function
str1 = "10.23"
str2 = "1001"
# printing str1 & str2 types
print("type of str1: ", type(str1))
print("type of str2: ", type(str2))
# converting to float value
val1 = float(str1)
val2 = float(str2)
# printing types and values of val1 & val2
print("type of val1: ", type(val1))
print("type of val2: ", type(val2))
print("val1 = ", val1)
print("val2 = ", val2)
Output
The output of the above example is:
type of str1: <class 'str'>
type of str2: <class 'str'>
type of val1: <class 'float'>
type of val2: <class 'float'>
val1 = 10.23
val2 = 1001.0
Parsing a string input to the float
Generally, when we take input using the input() method, it returns a string value. To parse the string input to the float, use the input() method inside the float() method.
Remember, the input should be either a float or an int value.
Python program to parse a string input to the float
# Input and parse a float value
value = float(input("Input a float value : "))
# Printing the type and value
print("Type of the value is :", type(value))
print("And, the value is :", value)
Output
The output of the above example is:
RUN 1:
Input a float value : 12.34
Type of the value is : <class 'float'>
And, the value is : 12.34
RUN 2:
Input a float value : 108
Type of the value is : <class 'float'>
And, the value is : 108.0
RUN 3:
Input a float value : 108Hello
Traceback (most recent call last):
File "/home/main.py", line 3, in <module>
value = float(input("Input a float value : "))
ValueError: could not convert string to float: '108Hello'