What are metaclasses in python programming?

[utkarsh112233]

Metaclasses are known among the most advanced features of the Python programming language. In order to understand metaclasses in python programming, you must first master Python classes.

The definition of a class in most programming languages is simply how to make an object. In Python, a metaclass is a subclass of a class that defines how the parent class behaves. A class is merely an instance of a metaclass. In Python programming language, a class defines how an instance of the class behaves.

Whenever we call a class to create a class, the metaclass is the one that does the magic of creating the class. We can compare metaclasses to classes by saying that while classes are blueprints for objects, metaclasses are blueprints for classes. Furthermore, class acts as a blueprint when an instance is created whereas metaclass acts as a blueprint only if you define that class.

The simplest implementation of a metaclass that does not alter anything looks as follows:

# inherit from type
class MyMeta(type):
# __new__ is a classmethod, even without @classmethod decorator
def __new__(cls, name, bases, namespace):
# cls - MyMeta
# name - name of the class being defined (MyClass in this example)
# bases - base classes for constructed class, empty tuple in this case
# namespace - dict with methods and fields defined in class
# in this case - {'x': 3}

# super().__new__ just returns a new class
return super().__new__(cls, name, bases, namespace)

class MyClass(metaclass=MyMeta):
x = 3

Application of metaclasses:

You can use Metaclasses in python programming while logging, registration of classes at creation, and profiling among others. Several other uses cases of metaclasses in python programming are enforcement of conventions, guiding implementation, or enabling easy extendability.

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Title: How to create pyramids using python pattern programs?

Python pattern programs are an excellent way to create patterns like pyramids. One can create a pyramid structure simply with the help of loop and range functions in python programming. To begin creating shapes with the help of python programming, we must understand python for loop and range function first. For loops are traditionally used when you want a source code to be repeated a fixed number of times. Python iterates over each of the elements of a sequence, executing each block simultaneously. With the 'range' function, Python returns a sequence of elements following a specific pattern, meeting the requirement of providing a sequence for a statement to iterate over.

Here are some of the most common pyramid examples with their codes and the output we get when we run that code.

Pattern 1: A right-angle pyramid pattern.

Code:

def pyramid(p):
for m in range(0, p):
for n in range(0, m+1):
print("* ",end="")
print("\r")
p = 10
pyramid(p)

Output:

*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * * * *

Pattern 2: An isosceles triangle. Here, two of the three sides of the triangle are of equal length.

Code:

n = 0
r = 12
for m in range(1, r+1):
for gap in range(1, (r-m)+1):
print(end=" ")
while n != (2*m-1):
print("* ", end="")
n = n + 1
n = 0
print()

Output:
*
* * *
* * * * *
* * * * * * *
* * * * * * * * *
* * * * * * * * * * *
* * * * * * * * * * * * *
* * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * *

Pattern 3: An equilateral triangle. Here, all the three sides of the triangle are of the same length.

Code:

length = 12
k = (2 * length) - 2
for p in range(0, length):
for n in range(0, k):
print(end=" ")
k = k - 1
for n in range(0, p + 1):
print("@", end=' ')
print(" ")

Output:

@
@ @
@ @ @
@ @ @ @
@ @ @ @ @
@ @ @ @ @ @
@ @ @ @ @ @ @
@ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @


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[sellian]

I didn't understand a thing but yesterday I regged metaclass.es

Is my domain valuable now?