Python int() Function
Python int() function returns an integer from a given object or converts a number in a given base to a decimal.
Example:
In this example, we passed a string as an argument to the int() function and printed it.
Python3
age = "21"print("age =", int(age)) |
Output:
age = 21
Python int() Function Syntax
The syntax of the int() function in Python is as follows:
Syntax: int(x, base)
- x [optional]: string representation of integer value, defaults to 0, if no value provided.
- base [optional]: (integer value) base of the number.
Returns: Return decimal (base-10) representation of x
Python int() Function Examples
Let us see a few examples of int() in Python.
Python int() with different DataTypes
In this example, we passed a string, a float, and an integer value as a parameter to the int() function in Python to see how the input is affected by applying the int() function.
Python3
# int() on string representation of numbersprint("int('9')) =", int('9'))# int() on float valuesprint("int(9.9) =", int(9.9))# int() on Python integerprint("int(9) =", int(9)) |
Output :
int('9')) = 9
int(9.9) = 9
int(9) = 9
Convert base using int() in Python
In this example, we used the int() function to convert the base of a number from Binary, Octal, and Hexadecimal to a Decimal integer.
Python3
# octal to decimal using int()print("int() on 0o12 =", int('0o12', 8))# binary to decimal using int()print("int() on 0b110 =", int('0b110', 2))# hexa-decimal to decimal using int()print("int() on 0x1A =", int('0x1A', 16)) |
Output :
int() on 0o12 = 10 int() on 0b110 = 6 int() on 0x1A = 26
Exception of int() in Python
TypeError: raises TypeError when any object that does not have __int__() or __index__() Python magic methods implemented.
ValueError: raises ValueError when any object cannot be converted to an integer.
TypeError: int() can’t convert non-string with explicit base
In this example, we are trying to convert a binary number to a decimal number using the Python int() function. But this code will raise an error as the binary number passed is not in a single quote.
Python3
print(int(0b101, 2)) |
Output :
TypeError: int() can't convert non-string with explicit base
ValueError: invalid literal for int() with base 10: ‘geeks’
This example will generate a value error as we are passing a Python String to the int() function.
Python3
print(int('geeks')) |
Output:
ValueError: invalid literal for int() with base 10: 'geeks'
Python int() Function for Custom Objects
The int() in Python can be used on custom objects. Let us see a few examples of the same.
int() with __int__() function
In this example, we created a class called ‘Number’ and defined a value and a constructor that returns the value. Then we created an object called ‘data’ of the Number class which invokes the __init__() method. The data object stores the value that is returned by that method and then using the int() function we printed the value.
Python3
class Number: value = 7 def __int__(self): return self.valuedata = Number()print("number =", int(data)) |
Output:
number = 7
int() with __index__() function
In this example, we created a class called ‘Number’ and defined a value and a function that returns the value. Then we created an object called ‘data’ of the Number class which invokes the __index__() method. The data object stores the value that is returned by that method and then using the int() function we printed the value.
Python3
class Number: value = 7 def __index__(self): return self.valuedata = Number()print("number =", int(data)) |
Output:
number = 7
Application
The int() function in Python is used in all the standard conversions. For example, the conversion of binary to decimal, octal to decimal, and hexadecimal to decimal.
