{"id":4757,"date":"2022-09-14T01:54:29","date_gmt":"2022-09-14T01:54:29","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=4757"},"modified":"2022-09-14T02:30:41","modified_gmt":"2022-09-14T02:30:41","slug":"python-id","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/python-built-in-functions\/python-id\/","title":{"rendered":"Python id()"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the Python id()<\/code> function to get the identity of an object.<\/p>\n\n\n\n

Introduction to the Python id() function #<\/a><\/h2>\n\n\n\n

The id()<\/code> function accepts an object and returns an integer<\/a> that identifies that object:<\/p>\n\n\n

id(object)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The returned integer is unique and doesn’t change during the lifetime of the object.<\/p>\n\n\n\n
In Python, everything is an object including a number, a string, etc. For example:<\/p>\n\n\n
x = 10<\/span>\nprint(id(x))  # 2523002569232<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The id(x)<\/code> returns an integer (2523002569232<\/code>) that is corresponding to the memory address of the object that x<\/code> references.<\/p>\n\n\n\n
Note that you’ll see a different integer number every time you run the program.<\/p>\n\n\n\n
To convert the memory address from an integer to hexadecimal, you use the hex()<\/a><\/code> function:<\/p>\n\n\n
x = 10<\/span>\nprint(id(x))  # 2304409666064<\/span>\nprint(hex(id(x)))  # 0x24b6eac0210<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The following defines two variables x and y and assigns 10 to both:<\/p>\n\n\n
x = 10<\/span>\ny = 10<\/span>\nprint(id(x) == id(y))  # True<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
In this case, Python creates only one<\/em> integer object with the value of 10 and references both the x and y variables to it. Therefore, the identity of the object that x and y reference is the same:<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Python does the same way for string objects. For example:<\/p>\n\n\n
a = 'Python'<\/span>\nb = 'Python'<\/span>\nprint(id(a) == id(b))  # True<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
  • Use the id()<\/code> function to get an integer, which is an identity of an object.<\/li><\/ul>\n
    \n\t
    \n\t\t
    Was this tutorial helpful ?<\/div>\n\t\t
    \n\t\t\t\n\t\t\t\t\n\t\t\t\t\t<\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t\n\t\t\t\t\n\t\t\t\t\t<\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t
    \n\t\t
    \n\t\t\t
    <\/div>\n\t\t\t
In this example, we define a variable x<\/code> and set it to 10. Internally, Python creates a new integer object and references<\/a> x<\/code> to that object in the memory. <\/p>\n\n\n\n