Answers for "call class in python"

what is a class in python

Classes are blueprint used to construct objects

class methods parameters python

class Foo          (object):
    # ^class name  #^ inherits from object

    bar = "Bar" #Class attribute.

    def __init__(self):
        #        #^ The first variable is the class instance in methods.  
        #        #  This is called "self" by convention, but could be any name you want.
        #^ double underscore (dunder) methods are usually special.  This one 
        #  gets called immediately after a new instance is created.

        self.variable = "Foo" #instance attribute.
        print self.variable, self.bar  #<---self.bar references class attribute
        self.bar = " Bar is now Baz"   #<---self.bar is now an instance attribute
        print self.variable, self.bar  

    def method(self, arg1, arg2):
        #This method has arguments.  You would call it like this:  instance.method(1, 2)
        print "in method (args):", arg1, arg2
        print "in method (attributes):", self.variable, self.bar


a = Foo() # this calls __init__ (indirectly), output:
                 # Foo bar
                 # Foo  Bar is now Baz
print a.variable # Foo
a.variable = "bar"
a.method(1, 2) # output:
               # in method (args): 1 2
               # in method (attributes): bar  Bar is now Baz
Foo.method(a, 1, 2) #<--- Same as a.method(1, 2).  This makes it a little more explicit what the argument "self" actually is.

class Bar(object):
    def __init__(self, arg):
        self.arg = arg
        self.Foo = Foo()

b = Bar(a)
b.arg.variable = "something"
print a.variable # something
print b.Foo.variable # Foo

python class with function @classmethod

import numpy as np 

class Unknown:
    def __init__(self, p1, p2, p3, p4):
        self.p1 = p1
        self.p2 = p2
        self.p3 = p3
        self.p4 = p4

    def random_func(self, p5):
        '''Function that return an array from a range,
        with specified shape, and name'''
        step1 = np.array(np.arange(self.p1)).reshape((self.p2,self.p3))
        step2 = self.p4
        print(step2)
        print('Printing p5 =>', p5)
        return step1

    @classmethod
    def a_class_method(self, p6):
        print(f'This is a class method: {p6}')
        
        

#PREPARE PARAMS 
# cust_arr = random_func(self.p1, self.p2, self.p3, self.p4)
params = {'p1':12, 'p2':3, 'p3':4, 'p4':'Creating customized array with params'}

#INSTANCIATE
here = Unknown(**params)#16, 4, 4, 'This actually work too!')
here.random_func('This is P5')
Unknown.a_class_method('P6 value is now used !')