Python String to Float

In Python, when an input is received during a terminal operation such as reading or writing a file or performing a file operation, the input becomes a string object. Even if you are requesting a float number, the input method gets the input as a string. Therefore, we directly change the string to a float number so that we carry out the appropriate operation thereon.

The characters we entered are changed into binary format. Different encoding techniques (Unicode and ASCII) are used for this conversion. In Python, the modification of data type is very common. Python has a feature that makes this easy. In this situation, we change the number from a string to a float until using the operation. It is utilized to show the floating number. Float is usually expressed with decimal points.

Python contains different type conversion functions that change one data type directly to others. This guide is proposed to provide details on how to convert strings to floats. In Python, different ordinary and straightforward ways are used to change a string to float.

Use Float() Method

We use the float () function to alter a string to float in Python. This function accepts only one parameter. If no arguments are passed, the approach returns 0.0.

If the input string has arguments outside the floating-point range, an Overflow error will be produced. The float() function calls the specified object.

For the implementation of codes in Python, spyder5 is installed on the laptop. Firstly, a new project is created after pressing the “Ctrl+N” from the keyboard. The name of our new file is “temp.py12”.

In this example, we take the string “3.4576”. We convert this string by passing the float() function. After passing this function, the string is converted into float. Now run the code by tapping the “Run” option from the menu bar of spyder5.

Converting a String Having Commas

In this code, the input string is “3,2.759”. The string has numbers, but it also contains commas. Hence, it is very difficult to change this type of string to a floating-point value. Calling the float () function directly results in an error in the output.

Before we call the float() function, we have to get rid of the comma from the string. If we call the float() function directly it shows an error. So, we remove the comma from the string by using replace() function. The replace() function shows that the comma in the string is replaced by the space in the string.

After removing the comma from the string, the float value of the string is “32.759”.

Converting a List of Strings

In Python, there is a list, which contains all the characters as a string in it. We iterate over each element of the list using a for loop. We have done this by changing the list of strings to float. Furthermore, we utilize the float () function to change every element to a float and reattach it to the list.

In this example, the input string is ” ‘12.23’, ‘45.78’, ‘69.34’, ‘38.65’ “. Here we use a for loop to recapitulate every element of the list. After this, we pass the float() function to change the list of strings into floats.

After passing the float() function, the list of a string is changed into float numbers.

Converting a String with Defined Decimal Points

Sometimes, we would like to specify the number of zeros afterward the decimal point within the float value. In this situation, we use the float () function. After that, we use the format () function to define the number of decimal places within the float.

The input string is “6.759104”. We want just 4 digits after the decimal point within the float value. We apply the format() function for this thing.

Here, format() method is also used to define the number of decimal places within the float. If the created floating-point value has fewer decimal places than the recommended value, round it off by adding zeros at the end.

So after applying the format() function, the float value is “6.7591”.


In Python, there are such cases in which one type of data needs to be changed to another to perform the required operation. This article is related to the Python string and floating-point values intimately and hence different approaches that are used to change the strings to float values. Python’s input methods accept String objects, so to perform various operations on user data, finding out these methods to convert strings to float data types is needed.

The string must have a float value. Otherwise, float () returns ValueError. If the element is outside the floating variable range, it shows OverflowError in output. If there is no value as an argument, it returns 0.0.

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Kalsoom Bibi

Hello, I am a freelance writer and usually write for Linux and other technology related content