Python Tutorial for Beginners 16 - Class Constructors (__init__) and Destructor (__del__)

In this Python Tutorial for Beginners video I am going to show How to use __init__ method and self self keyword in python. So what does the __init__ method do in python ? __init__ method is used as a constructor for the class. Usually __init__ does some initialization work e.g. initialize attributes and other functions.The arguments passed to the class name are given to its __init__() method. It would be incorrect to call __init__ constructor of the class.But __init__ is the closest thing we're going to get in Python to a constructor.
And what is self in python - self is the first argument of every method is a reference to the current instance of the class. self keyword is similar to the keyword this in Java or C++.

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[vivektiwari]

sir i think we don't need to call personName.__del__() . It will be called automatically when we will delete the object with the help of del keyword. Ex: del personName.

When we call the __del__() method explicitly the object is not destroyed
but with del object is destroyed

[devrajkanti]

Do we need to call the destructor explicitly? As I haven't called the destructor explicitly but the contents under function __del__ were printed.

[hmhamam_ham]

I love you... You saved my life with this.

[lienestankevica]

Last 2 videos are really confusing. I have no other programming knowledge but from these videos. Therefore it's hard to understand what exactly is a class, how and why it can be used. Also I didn't get what do those dots as sepreators mean. And why I need to use expressions with dot seperators and then define them to be equal with expression without dot. And that "Self" - is it inbuilt python default something or what?
Other videos were really well explained but these two..

[EchoBravo]

When you explicitly call __del__() with a print message only, is it really deletes the 'p' object?
eg:
>>> class Person:
... def __init__(self):
... print("init")
... def __del__(self):
... print("deleted")
...
>>> p=Person()
init
>>> p
<__main__.Person instance at 0xb723c5ec>
>>> p.__del__()
deleted
>>> p
<__main__.Person instance at 0xb723c5ec>
>>>

here you see that 'p' is still pointing to a memory even after delete.

[ermanishkumar]

Hi...Thank you for the course.
I have a doubt as "why Id: 5 is reprinted in this program", when Destructor (__del__) already destroy the instance of a class.

class Person: # Creating a Person class
def __init__(self, id):
self.id=id
print ("Id:", self.id, " - Our class is created")
def __del__(self):
print ("Id:", self.id, " - Our class object is destroyed")
def setFullName (self, firstName, lastName): # 1st member Function: Setting the member function inside class i.e. First Name & Last Name. "self" is default when we use funtion inside class which is nothing but the pointer to the class.
self.firstName=firstName # Setting First Name variable of the class using self
self.lastName=lastName # Setting Last Name variable of the class using self
def printFullName (self): # 2nd member Function: To print with No argument required to print Full Name
print (self.firstName, " ", self.lastName) # To print First Name & Last Name

personName=Person(5) # Creating Instanse of a class. Start from the corner to be outside of the class. Take care of indentation
personName.setFullName("Programming", "Language") # Using member function setFullName of the Person class. "self" will be taken automatically and just pass other arguments
personName.printFullName()
personName.__del__()
personName=Person(6) # Entering another id, even working with same id=5, similar result
personName.__del__()


>>>

RESTART


Id: 5 - Our class is created
Programming Language
Id: 5 - Our class object is destroyed
Id: 6 - Our class is created
Id: 5 - Our class object is destroyed
<--- why Id: 5 is reprinted in this program.
Id: 6 - Our class object is destroyed
>>>

[bhoopeshrajpoot]

Is that any stage in program code when destructor(__del__) automatically call . LIKE Constructor

[linglindaband]

why self.id in the constructors function can be used in destructor again? Isn't one specific statement under one function can only be used under that function?

[vijyantvibhu]

Can you please help me to understand, how the destructor method(__del__) is doing the garbage collection. In the video i could only see that the method is just printing a message.

[ramakrishna]

sir i got an error like this will you explain it for me (Traceback (most recent call last):
File "C:/Users/user/AppData/Local/Programs/Python/Python39/class.py", line 7, in <module>
personName=Person()
NameError: name 'Person' is not defined) please sir

[sateeshpasumarthi]

if __del__(): is a destructor, then why it is not been called when object goes out of scope? you said garbage collect, isnt it applied here?

[chitralalawat]

your all tutorials are very gud except this and the tuto 15... it's creating imbroglio... they are not well explanatory.. please elaborate if you can... why we are using self, parenthesis, parameters, __init__ on the top, its role etc etc

[SamSantiagoMaximoAPIs]

when we initlz id in __init__ it will automatically knows its data type or what??

[Router]

Please make vids on how to make a real programme for a computer

[bingli]

Could you further explain "destructor" ? Why it is called garbage collect?

[parkerzhang]

why was the __del__() not triggered in the first place?

[surya]

How to fix " inconsistent use of indents and tabs " error

[thuyvuong]

not sure what I typed is wrong it says invalid syntax and highlights the __init__ portion of code.

Here is my code I am trying to run:

class Person:
def __ init__(self):
print("Our class is created")
def setFullName(self, firstName, lastName):
self.firstName= firstName
self.lastName= lastName
def printFullName(self):
print(self.firstName, " ", self.lastName)

personName= Person()
personName.setFullName("programming", "Knowledge")
personName.printFullName()

[lokeshloki]

something wrong in the video.you should call del() function on the object inorder for __del__ to call.direct call to __del__ looks very funny

[ashishmishra-ebun]

how id is printed, since we have not passed any command to print it??