class class pass Error

print(p1.age), Delete Object Properties Usually set automatically by a script. We accomplish this by creating thousands of videos, articles, and interactive coding lessons - all freely available to the public. print("Hello my name is " + self.name), p1 = Person("John", 36) This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below.

print("Hello my name is " + self.name) MyClass , class MyClass: p1.age = 40 print(p1.age), Traceback (most recent call last): p1, class Person: The usual way of using __name__ and __main__ looks like this: Let's see how this works in real life, and how to actually use these variables. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. File "demo_class8.py", line 13, in p1 = Person("John", 36) object p1, class Person: # Due to bootstrapping issues we need to import exceptions here. p1 = Person("John", 36) print(p1.age), Modify Object Properties To run one of these functions modify the if __name__ == "__main__" part of file_one to look like this: When running file_one you should see should be like this: Also, you can run functions from imported files. But run file_two directly and you will see that its name is set to __main__: The variable __name__ for the file/module that is run will be always __main__. p1.age = 40 print(p1.age), Traceback (most recent call last): Check out more articles like this on my freeCodeCamp profile, Medium profile, and other fun stuff I build on my GitHub page. 085-350-7540 , 084-88-00-255 , ntprintf@gmail.com, Expert Programming Tutor Class and Objects, class Person, , LM73PYTHON HOWTO REMOVE DUPLICATES FROM A PYTHON LIST, LM74PYTHON HOW TO REVERSE A STRING IN PYTHON, LM75PYTHON HOW TO ADD TWO NUMBERS IN PYTHON, https://www.w3schools.com/python/python_classes.asp, https://elearn.expert-programming-tutor.com, 9 Reasons Your Child Should Learn to Code, 14 What Will AIs Biggest Contribution To Healthcare Be, MT003 8 Fun Machine Learning Projects For Beginner, MT006 Top 20 Python Machine Learning Open Source Projects, MT102 Introduction to Deep Learning with TensorFlow, MT103 Installing TensorFlow for Deep Learning, MT104 TensorFlow Creating the Neural Network Model, MT105 TensorFlow How the Network will run, MT203 How to program a quantum computer PART1, MT204 How to program a quantum computer PART2, LM16PYTHON 10NUMPY TRIGONOMETRIC FUNCTIONS, LM18PYTHON MACHINE LEARNING MEAN MEDIAN MODE, LM19PYTHON MACHINE LEARNING STANDARD DEVIATION, LM21PYTHON MACHINE LEARNING DATA DISTRIBUTION, LM22PYTHON MACHINE LEARNING NORMAL DATA DISTRIBUTION, LM24PYTHON MACHINE LEARNING LINEAR REGRESSION, LM25PYTHON MACHINE LEARNING MULTIPLE REGRESSION, LM25PYTHON MACHINE LEARNING POLYNOMIAL REGRESSION, LM28PYTHON MACHINE LEARNING DECISION TREE, VDO0003 PY801 Data Sci Data Analyst with Python 01, VDO0004 PY801 Data Sci Data Analyst with Python 02, VDO0006 Lets Learn Web Programming Easy Version, Course SET Course , Course Level Up - , Course Level Up - (), Course ESSENTIAL COURSE ( Private ), Course 1-2 . Now run file_two and you will see that the __name__ variable is set to __main__: When modules like this are being imported and run, their functions will be imported, and top level code executed. class # The majority of the functions and classes provided by Werkzeug work on the, # HTTP and WSGI layer. But the __name__ variable for all other modules that are being imported will be set to their module's name. Werkzeug is the Swiss Army knife of Python web development. __init __ () __init __ () __init __ () self.age = age When a Python interpreter reads a Python file, it first sets a few special variables. # module will then lazily import from the modules that implement the objects. :license: BSD, see LICENSE for more details. self.name = name Learn more about bidirectional Unicode characters. Reading the file executes all top level code, but not functions and classes (since they will only get imported). 084-88-00-255 (AIS) self.age = age The self Parameter The downside of that is, that now everything would be loaded at, # The implementation of a lazy-loading module in this file replaces the, # werkzeug package when imported from within. We also have thousands of freeCodeCamp study groups around the world. We can use an if __name__ == "__main__" block to allow or prevent parts of code from being run when the modules are imported. del() print(p1.age), : __init __ () Software enginner with experience in developing, testing and maintaining software solutions. You can make a tax-deductible donation here. Modify file_one and file_two to look like this: Again, when running file_one you will see that the program recognized which of these two modules is __main__ and executed the code according to our first if else statements. class Person Let's take a look at an example. self.name = name To review, open the file in an editor that reveals hidden Unicode characters. Learn to code for free. del p1.age 026-111-618 Create a Python module named file_one.py and paste this top level code inside: By running this file you will see exactly what we were talking about. You signed in with another tab or window. self.age = age Working in agile, entrepreneurial, high paced global company. :copyright: (c) 2014 by the Werkzeug Team, see AUTHORS for more details. print(p1.age) self.age = age, def myfunc(self): Then it executes the code from the file. def myfunc(self): def __init__(self, name, age):

self.name = name p1 = MyClass() | 085-350-7540 | 084-88-00-255 | ntprintf@gmail.com, . NameError: 'p1' is not defined, The pass Statement Python Python Class "blueprint"" Object Methods To do that, modify the if __name__ == __main__ part of file_one to look like this: Now let's say the file_two module is really big with lot of functions (two in our case), and you don't want to import all of them. , class Person: class print(p1) This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. One of those variables is called __name__. When the Python interpreter reads a file, the __name__ variable is set as __main__ if the module being run, or as the module's name if it is imported. If you follow this article step-by-step and read its code snippets, you will learn how to use if __name__ == "__main__", and why it's so important. The variable __name__ for this module is set to __main__: Now add another file named file_two.py and paste this code inside: Also, modify the code in file_one.py like this so we import the file_two module: Running our file_one code once again will show that the __name__ variable in the file_one did not change, and still remains set to __main__. del p1.age AttributeError: 'Person' object has no attribute 'age', : self def __init__(self, name, age): Cannot retrieve contributors at this time. def myfunc(self): def __init__(self, name, age): self.age = age """, # keep a reference to this module so that it's not garbage collected, # setup the new module and patch it into the dict of loaded modules. A module can define functions, classes, and variables. https://www.w3schools.com/python/python_classes.asp, 085-350-7540 (DTAC) Person __init __ () , class Person: So when the interpreter runs a module, the __name__ variable will be set as __main__ if the module that is being run is the main program. pass self.name = name # import mapping to objects in other modules, # modules that should be imported when accessed as attributes of werkzeug, """Automatically import objects from the modules. Get started, freeCodeCamp is a donor-supported tax-exempt 501(c)(3) nonprofit organization (United States Federal Tax Identification Number: 82-0779546).

p1 = Person("John", 36) But now the variable __name__ in file_two is set as its module name, hence file_two. Modify file_two to look like this: And to import the specific functions from the module, use the from import block in the file_one file: There is a really nice use case for the __name__ variable, whether you want a file that can be run as the main program or imported by other modules. # and motivation is explained here in detail now. print(p1.x), __init __ () Attribute access to the werkzeug. Expert Programming Tutor Class and Objects But if the code is importing the module from another module, then the __name__ variable will be set to that modules name. (That means "Well done" in Swedish!). To see this process in action, modify your files to look like this: Now the functions are loaded but not run. There is no useful grouping for those which is why, # they are all importable from "werkzeug" instead of the modules where they are, # implemented. print("Hello my name is " + self.name), p1 = Person("John", 36) Python files are called modules and they are identified by the .py file extension. All of the provided, classes are independent from each other so you can mix it with any other. x = 5 # the version. It provides useful classes and functions for any WSGI application to make, the life of a python web developer much easier. # This import magic raises concerns quite often which is why the implementation. File "demo_class7.py", line 13, in Donations to freeCodeCamp go toward our education initiatives, and help pay for servers, services, and staff. MyClass x, Objects Our mission: to help people learn to code for free. def __init__(self, name, age): All rights reserved. # having an empty class definition like this, would raise an error without the pass statement, Class and Objects p1 40, class Person: print("Hello my name is " + self.name) def myfunc(self): EMAIL: NTPRINTF@GMAIL.COM, Copyright (c) 2013 expert-programming-tutor.com. Bra gjort! del() def __init__(self, name, age): p1, Delete Objects print(p1.name) mysillyobject abc self, class Person: self.name = name