Python Type Conversion and Type Casting

John on June 14, 2021

Typecasting in Python is the process of converting an item with a particular data type to another data type.

In Python we can use the built-in int(), float() and str() functions to convert the data type of any item to an integer, floating-point number or string provided the literal contains appropriate values.

Type Cast int to float

To cast an int to a float, use the Python float() function and pass the value to change as the first argument:

i = 92

f = float(i)

print(f)
print(type(f))

92.0
<class 'float'>

As you can see from the output, the number is now cast as class 'float'. It is important to note that the float() function does not modify the original variable.

Type Cast float to int

To cast an integer, use the int() function and pass the floating-point number to change as the first argument:

f = 92.1

i = int(f)

print(i)
print(type(i))

92
<class 'int'>

Note – no rounding is done with the int() function, the decimal place is simply removed.

Type Cast string to int and float

Strings can also be changed to floats and integers like this:

s = '92.1'

f = float(s)
i = int(f)

print(i)
print(type(i))

print(f)
print(type(f))

92
<class 'int'>
92.1
<class 'float'>

If the string contains a float, it must be cast as a float before casting to an integer or you will get a ValueError.