Class Introduction.py

# A Class is like an object constructor
# A class is a user-defined blueprint for Creating Object
# class (Class Name) :
#     Statement or Attributes

# Attributes --->
                # 1) Properties
                # 2) Method/Constructor

# Class Create and Operation
class student :
    name = "Aubdur Rob Anik"
    roll = 18101073

    def write(self): # Here self means object name.
        print("Student Name is :: ", self.name)
        print("Student Roll is :: ", self.roll)

#When an object of a class is created, the class is said to be instantiated
std1 = student()
std1.write() #-----> It's Call Like : student.write(std1)

# Method Use For Initialization Properties
# By built-in Function
class student :
    def __init__(self, name, semester) :
        self.name = name   #properties
        self.semester = semester  #properties

    def write(self):
        print("Student Name is :: ", self.name)
        print("Student Semester is :: ", self.semester)

st1 = student("Aubdur Rob Anik", "1-1") #Constructor
st1.write()

# Another Way
# Method Use For Initialization
# By User Defined Function
class person :
    def set_value(p1, name, age):
        p1.name = name  # Not Properties
        p1.age = age    # Not Properties

    def write(p1):
        print("Person Name :: ", p1.name)
        print("Person Age :: ", p1.age)

person1 = person()
person1.set_value("Aubdur Rob Anik", 14)
person1.write()

#Class Variable
class person :
    occupation = "Student"  #Class Variable

    def __init__(self, name, age):
        self.name = name
        self.age = age

p1 = person("Aubdur Rob Anik", 14)

print("Person 1 is a :: ", p1.occupation)
print("Person 1 Name :: ", p1.name)
print("Person 1 Age :: ", p1.age)

#Return Value From A Class method
class dress :
    def __init__(self, size):
        self.size = size

    def setcolor(self, color):
        self.color = color

    def getcolor(self):
        return self.color

pant = dress("M")
pant.setcolor("Black")
print("Pant Color is :: ", pant.getcolor())

# __dict__ is a built in function
# __dict__ function is a Dictionary of class and object
#attribute save as a dictionary.

class person :
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def write(self):
        print("Person Name :: ", self.name)
        print("Person Age :: ", self.age)

p1 = person("Aubdur Rob Anik", 14)
p2 = person("Jafrin", 13)

print()
print(person.__dict__)
print(p1.__dict__)
print(p2.__dict__)

#object property add
class person :
    occupation = "Student"

    def __init__(self, name, age):
        self.name = name
        self.age = age

    def write(self):
        print("Name :: ", self.name)
        print("Occupation :: ", self.occupation)
        print("Age :: ", self.age)

p1 = person("Aubdur Rob Anik", 14)
p1.roll = 18101073
p1.email = "anik13331@gmail.com"

p1.write()
print("Roll :: ", p1.roll)
print("Email :: ", p1.email)


#Attribute Input
class information :
    university = "UAP"

    def __init__(self, name, id, department):
        self.name = name
        self.id = id
        self.department = department

    def write(self):
        print("Name :: ", self.name)
        print("University :: ", self.university)
        print("ID :: ", self.id)
        print("Department :: ", self.department)


std1 = information(input("\nName :: "), input("ID :: "), input("Department :: "))
std2 = information(input("\nName :: "), input("ID :: "), input("Department :: "))
std3 = information(input("\nName :: "), input("ID :: "), input("Department :: "))

std1.write()
std2.write()
std3.write()

#__str__ method
# The __str__ method in Python classes is used to define the string
# representation of an object. When you call the built-in str() 
# function or use print() on an object, Python internally invokes 
# the __str__ method of that object to determine how it should 
# be represented as a string

class information:
    university = "UAP"

    def __init__(self, name, age, department):
        self.name = name
        self.age = age
        self.department = department

    def __str__(self):
        return f"{self.name}-{self.age}-{self.department}-{self.university}"

p = information(input("Name : "), input("Age: "), input("Department: "))
print("Student Information : ", p)