How to build an e-commerce shop with Python, Django, & Wagtail

“D-J-A-N-G-O. The D is silent.”

“D-J-A-N-G-O. The D is silent.”

Man, I love that line. So badass.

But the eponymous character from Quentin Tarantino’s masterpiece isn’t the only badass Django in town.

So is the popular Python framework of the same name.

Today, I’m leaving the realm of JavaScript frameworks for a quick venture into Django e-commerce.

In this post, I’ll answer legitimate questions you might have when starting a new e-commerce project, such as:

Is Python the right language for my project? And Django the right framework? Which tools or plugins should I use?

Then, I’ll show you our homemade recipe for Django-powered e-commerce success with a step-by-step Wagtail CMS tutorial:

  • Creating a new Wagtail site.
  • Adding Snipcart configuration settings.
  • Generating database migrations.
  • Creating new products for your Django store.
  • Crafting an e-commerce template.

Let’s start with the basics.

The State of Python

One of the main reasons to pick Django as a framework is its Pythonfoundation.


A general purpose, dynamic programming language, Python was developed by ex-Googler Guido van Rossum in the late 80’s. A fan of Monthy Python, he took one-half of the name to baptize his programming project.

He wasn’t joking though. To say that Python has become “popular” is an understatement.

Today, it’s used by hundreds of thousands of developers all over the world. As StackOverflow puts it:

The term “fastest-growing” can be hard to define precisely, but we make the case that Python has a solid claim to being the fastest-growing major programming language.

A few reasons explain the Python love:

  • Its grammatical readability is awesome.
  • It has a fast learning curve for newcomers.
  • It boasts a long-lasting, solid ecosystem of libraries & community
  • It’s now the standard language for data science & machine learning.
  • It powers great dev tools like Pelican, a neat static blog generator.
  • Reddit is written in Python. ;)

What about the Django framework?

Django is an open source, high-level Python web framework. Its emphasis on reusable components makes it faster for developers to build web apps on top of Python. It presents itself as a web framework for perfectionists with deadlines.

Now maintained by the Django Software Foundation, it was originally written by two brilliant Lawrence Journal-World developers. Oh, and while Python draws its name from comedy icons, Django got his from a versatile guitar legend: Django Reinhardt!

As a full-stack framework, it overshadows pretty much any alternative tool out there. It’s fast, fully loaded, secure, scalable & versatile. All characteristics you’ll probably want to apply to your e-commerce setup!

Why use Django for e-commerce?

While you can do a lot with Django, let’s keep the focus on what it brings to e-commerce and the different tools available to put together an online store.


First, here are some Django features to consider if you’re looking for the right framework to build a shop.

→ Scalability

Django is perfect for e-commerce startups, as it’s a good fit for small websites, but also has scales perfectly with business growth. You can rely on Django to handle hundreds/thousands of visitors at a time. It’s built with independent components you can unplug or replace depending on your needs at any specific time.

→ Security

With e-commerce, you want to make sure merchants and clients alike feel safe through your shopping experience. Django prevents a whole lot of common security mistakes which often are what weakens traditional PHP CMSs. For instance, Django hides your site’s source code from direct viewing on the web by dynamically generating web pages.

→ Feature-rich

Compared to most frameworks, Django comes with way more features out-of-the-box. It allows you to build an app right off the bat. Perfect for supporting your online store with functionalities such as user authentification, content management or RSS feed. If something seems to be missing, you can count on Django’s community and plugins ecosystem to extend your app!

→ SEO-friendly

SEO is paramount for any online business. While other frameworks don’t natively play well with search engines (mainly JavaScript frameworks, like Vue or React), at least Django advocates best practices for SEO. Human-readable URLs and sitemap features are sure to please any marketing team.

Oh and also, it’s fast. Which is always great for both customer experience and SEO.

→ Reliable

It has been crowd-tested for a while now, and the community surrounding it is largely supportive. It’s continuously updated by active developers; maybe you’ll even find yourself contributing. ;)

There are a few noteworthy e-commerce solutions in the Python/Django ecosystem:

  • Oscar — Domain-driven e-commerce for Django, open-source.
  • Saleor — An e-commerce storefront written in Python, open-source.
  • Django-SHOP — A Django based shop system.
  • Shuup — A single and multi-vendor application.

You can explore more options through this extensive list of the best e-commerce packages.

Now let me present you another cool stack for a complete and custom e-commerce setup with Django.

Wagtail CMS + Snipcart e-commerce setup


Wagtail is a developer-first Django content management system. Free and open source, it was developed by the good-hearted folks at Torchbox. It’s elegant, flexible, and, IMHO, kicks ass.

In the following Wagtail tutorial, the CMS will be in charge of creating and managing products that users will then be able to buy through a shopping cart.

By the end of it, you’ll have a solid Django-powered e-commerce site up and running.

Let’s get practical!

Django e-commerce tutorial with Wagtail CMS

To continue with the movie references and because we’re working in Python, I’ll craft a Slytherin demo shop! Let’s see how it goes.

Pre-requisites

1. Creating a new Wagtail e-commerce site

Make sure you have Wagtail installed. If not, refer to their installation documentation.


Open a terminal and launch a new Wagtail site:

wagtail start snipcartwagtaildemocd snipcartwagtaildemoz

wagtail start snipcartwagtaildemo
cd snipcartwagtaildemo

We have an extra step to complete the Wagtail setup, and it’s to install the wagtail.contrib.settings plugin that we'll require later on.

In your new Wagtail project, open the base.py file located in settingsfolder. Then, add wagtail.contrib.settings to the INSTALLED_APPS array.

# ./setting/base.py
	INSTALLED_APPS = [
	    ...,
	    'wagtail.contrib.settings'
	]

1.1 Models definition

The first thing you need to do is create your Page models. Wagtail uses these Django models to generate a page type.


Open the models.py file located in the home folder of your product. This is where you'll define all your custom models.

Create two different models:

  • Product: defines the product you're selling.
  • ProductCustomField: defines a single product custom field.

Let’s begin by importing required modules:

# ./home/models.py
	from django.db import models
from modelcluster.fields import ParentalKey


from wagtail.core.models import Page, Orderable
from wagtail.admin.edit_handlers import FieldPanel, MultiFieldPanel, InlinePanel
from wagtail.images.edit_handlers import ImageChooserPanel

Now add the Product model:

# ./home/models.py

class Product(Page):
    sku = models.CharField(max_length=255)
    short_description = models.TextField(blank=True, null=True)
    price = models.DecimalField(decimal_places=2, max_digits=10)
    image = models.ForeignKey(
        'wagtailimages.Image',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='+'
    )


    content_panels = Page.content_panels + [
        FieldPanel('sku'),
        FieldPanel('price'),
        ImageChooserPanel('image'),
        FieldPanel('short_description'),
        InlinePanel('custom_fields', label='Custom fields'),
    ]

And ProductCustomField:

# ./home/models.py

class ProductCustomField(Orderable):
    product = ParentalKey(Product, on_delete=models.CASCADE, related_name='custom_fields')
    name = models.CharField(max_length=255)
    options = models.CharField(max_length=500, null=True, blank=True)


    panels = [
        FieldPanel('name'),
        FieldPanel('options')
    ]

2. Adding Snipcart configuration settings

If you need more help for this part, refer to our documentation here and here.

Let’s make sure you can update the Snipcart API key directly from Wagtail’s dashboard. You’ll need to add site settings to do so.

Site settings are special fields that you can add to your models file. They’ll appear in the Wagtail Settings section of the dashboard.

Import this module:

# ./home/models.py

from wagtail.contrib.settings.models import BaseSetting, register_setting

Then add these:

# ./home/models.py

@register_setting
class SnipcartSettings(BaseSetting):
    api_key = models.CharField(
        max_length=255,
        help_text='Your Snipcart public API key'
    )

3. Database migrations

Now that your models are created, you’ll need to generate database migrations and run them.


In your terminal, use the makemigrations command:

manage.py makemigrations

You should see the following output:

Migrations for 'home':
home\migrations\0003_product_productcustomfield_snipcartsettings.py
- Create model Product
- Create model ProductCustomField
- Create model SnipcartSettings

Once the migrations are generated, apply them on your database with the migrate command:

	manage.py migrate

It will take a couple of seconds; Wagtail will set up its own database schema along with the models you just defined.

Finally, create your first CMS user with the createsuperuser command:

manage.py createsuperuser

Don’t forget the username and password you picked — you will need them to log into Wagtail’s dashboard.

4. Creating products

Start by firing up your dev server with the Django dev server command:

manage.py runserver

Now open your browser and navigate to: http://localhost:8000/admin. Use the credentials you set up earlier to log in.

Select the Home page in Wagtail's menu. Then click on the Add child page button.

You’ll be asked to pick a type of page, select Product.

Enter the product details, then publish your new product:

You can create as many products as you wish.

4.1 Adding Snipcart API key

Remember the SnipcartSettings class you created? You'll be able to configure your API key by expanding the Settings menu and going to Snipcart settings.

Open Snipcart’s dashboard and get your public API key (Test or Live). Go back to Wagtail and paste it in the API key field.

Save your settings.

5. Templating

Your backend is now ready, your API key is configured, and your first products are created. Time to start building the site.


For this demo, I decided to use Spectre.css CSS framework. It’s straightforward and lightweight.

Open the base.html file located in snipcartwaigtaildemo/templates.

You’ll need to add references for Spectree.css and Snipcart. Add these lines in the head of your document:

<!-- ./snipcartwagtaildemo/templates/base.html -->
{% load static wagtailsettings_tags %}
{% get_settings %}

{# Global stylesheets #}


&lt;link rel="stylesheet" href="https://unpkg.com/spectre.css/dist/spectre.min.css"&gt;
&lt;link rel="stylesheet" href="https://unpkg.com/spectre.css/dist/spectre-exp.min.css"&gt;
&lt;link rel="stylesheet" href="https://unpkg.com/spectre.css/dist/spectre-icons.min.css"&gt;


{# Snipcart #}


{% if settings.home.SnipcartSettings.api_key %}
    &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"&gt;&lt;/script&gt;
    &lt;script src="https://cdn.snipcart.com/scripts/2.0/snipcart.js" id="snipcart" data-api-key="{{ settings.home.SnipcartSettings.api_key }}"&gt;&lt;/script&gt;
    &lt;link href="https://cdn.snipcart.com/themes/2.0/base/snipcart.min.css" type="text/css" rel="stylesheet" /&gt;
{% endif %}

The Snipcart API key that you configured previously is available via:

settings.home.SnipcartSettings.api_key

Then, add the navbar and some other Spectre.css layout elements.

Replace the content of the whole body by these lines:

<!-- ./snipcartwagtaildemo/templates/base.html -->
{% wagtailuserbar %}

&lt;div class="container grid-lg"&gt;
    &lt;header class="navbar"&gt;


        &lt;section class="navbar-section"&gt;
            &lt;a href="/" class="navbar-brand mr-2"&gt;
                Products
            &lt;/a&gt;
        &lt;/section&gt;


        &lt;!-- Snipcart summary and View cart button --&gt;
        &lt;section class="navbar-section snipcart-summary"&gt;
            &lt;div class="input-group input-line"&gt;
                &lt;a href="" class="btn btn-primary snipcart-checkout"&gt;
                    &lt;i class="icon icon-apps"&gt;&lt;/i&gt;
                    View cart (&lt;span class="snipcart-total-items"&gt;0&lt;/span&gt;)
                &lt;/a&gt;
            &lt;/div&gt;
        &lt;/section&gt;


    &lt;/header&gt;
&lt;/div&gt;


&lt;div class="container grid-lg"&gt;
    {% block content %}{% endblock %}
&lt;/div&gt;


{# Global javascript #}
&lt;script type="text/javascript" src="{% static 'js/snipcartwagtaildemo.js' %}"&gt;&lt;/script&gt;


{% block extra_js %}
    {# Override this in templates to add extra javascript #}
{% endblock %}

5.1 Listing products

The first template you need is your index, where products will be listed.


You’ll have to make your products available in your home page context. In any Wagtail Page, you can override a method name get_context.

You can add the data that the view will receive in parameters. In my case, I want to set the products context variable.

Open the models.py file in home folder and update the HomePage class:

# ./home/models.py

class HomePage(Page):
    def get_context(self, request):
        context = super().get_context(request)


        context['products'] = Product.objects.child_of(self).live()


        return context

Then, open the home_page.html file located in the home/templates/homefolder.

Let’s create a simple page that will show each product image with a link to the product details.

<!-- /.home/templates/home/home_template.html -->
{% extends "base.html" %}
{% load wagtailimages_tags %}

{% block content %}
    &lt;h1&gt;
        Welcome to our store
    &lt;/h1&gt;


    &lt;div class="columns"&gt;
        {% for product in products %}
            &lt;div class="column col-6"&gt;
                &lt;div class="card"&gt;
                    &lt;div class="card-image"&gt;
                        {% image product.image fill-1000x200 as tmp_image %}
                        &lt;img src="{{ tmp_image.url }}" alt="" class="img-responsive"&gt;
                    &lt;/div&gt;
                    &lt;div class="card-header"&gt;
                        &lt;a href="{{ product.get_url }}" class="btn btn-primary float-right"&gt;
                            &lt;i class="icon icon-plus"&gt;&lt;/i&gt;
                        &lt;/a&gt;
                        &lt;div class="card-title h5"&gt;
                            {{ product.title }}
                        &lt;/div&gt;
                    &lt;/div&gt;
                    &lt;div class="card-body"&gt;
                        {{ product.description }}
                    &lt;/div&gt;
                &lt;/div&gt;
            &lt;/div&gt;
        {% endfor %}
    &lt;/div&gt;
{% endblock %}

5.2 Product details

The last template is the one showing individual product details along with the Snipcart buy button.


Also, it would be nice to be able to select product options directly on this page, before adding it to the cart. So I’ll add a way to choose all custom fields with options directly in the template.

Before writing some HTML, you have to update the view context. Django templates don’t give us 100% access to all Python methods and objects, so things like splitting a string do not work very well.

I decided to override the get_context method again. Maybe there's a better way to do that—let me know in the comments below! ;)

Open models.py from the home folder and add this method in the Productclass:

# ./home/models.py

class Product(Page):


    def get_context(self, request):
        context = super().get_context(request)
        fields = []
        for f in self.custom_fields.get_object_list():
            if f.options:
                f.options_array = f.options.split('|')
                fields.append(f)
            else:
                fields.append(f)


        context['custom_fields'] = fields


        return context

A custom_fields array will be available in the product.html template.

Create a file named product.html in home/templates/home folder. This is the template that will be associated with the Product page model.

<!-- ./home/templates/home/product.html -->
{% extends "base.html" %}
{% load wagtailimages_tags %}

{% block content %}
    &lt;div class="container grid-lg"&gt;
        &lt;div class="columns"&gt;
            &lt;div class="column col-4"&gt;
                {% image page.image max-300x300 as temp_image %}
                &lt;img src="{{ temp_image.url }}" alt="" /&gt;
            &lt;/div&gt;
            &lt;div class="column col-8"&gt;
                &lt;h1&gt;
                    {{ page.title }}
                &lt;/h1&gt;


                &lt;p&gt;
                    {{ page.short_description }}
                &lt;/p&gt;


                &lt;p&gt;
                    {% for f in custom_fields %}
                        {% if f.options_array|length &gt; 0 %}
                            &lt;div class="form-group"&gt;
                                &lt;label class="form-label" for="{{ f.name|lower }}"&gt;
                                    {{ f.name }}
                                &lt;/label&gt;
                                &lt;select class="form-select custom-field-select" id="{{ f.name|lower }}" data-field="{{ forloop.counter }}"&gt;
                                    {% for opt in f.options_array %}
                                        &lt;option&gt;
                                            {{ opt }}
                                        &lt;/option&gt;
                                    {% endfor %}
                                &lt;/select&gt;
                            &lt;/div&gt;
                        {% endif %}
                    {% endfor %}
                &lt;/p&gt;


                &lt;button class="snipcart-add-item btn btn-primary"
                    data-item-name="{{ page.title }}"
                    data-item-id="{{ page.sku }}"
                    data-item-url="{{ page.get_full_url }}"
                    data-item-price="{{ page.price }}"
                    data-item-description="{{ page.short_description}}"
                    data-item-image="{{ temp_image.url }}"
                    {% for f in custom_fields %}
                        data-item-custom{{forloop.counter}}-name="{{f.name}}"
                        data-item-custom{{forloop.counter}}-options="{{f.options}}"
                    {% endfor %}&gt;
                    &lt;i class="icon icon-plus"&gt;&lt;/i&gt;
                    Add to cart
                &lt;/button&gt;
            &lt;/div&gt;
        &lt;/div&gt;
    &lt;/div&gt;
{% endblock %}

Then, add some JavaScript to update the Snipcart buy button when a custom field selection is made on the page.

Add the following script snippet before the endblock statement:

<script>
document.addEventListener('DOMContentLoaded', function() {
document.querySelector('.custom-field-select').onchange = function(event) {
if (event.target.dataset.field) {
document.querySelector('.snipcart-add-item')
.dataset['itemCustom' + event.target.dataset.field + 'Value'] = event.target.value;
}
};
},false);
</script>

This code updates the button data attributes when the select value changes.

If you click on the + button beside any product, you should see its details:

You now have pretty strong foundations to start your e-commerce project using Django and Wagtail!

These frameworks are very powerful. You could quickly add some search functionalities, product suggestions, reviews, etc.

Live demo & GitHub repo

See the live demo
See the GitHub repo

Closing thoughts

I really enjoyed working with Wagtail, as it’s simple and intuitive. I have to say that their documentation feels incomplete at times, though. At first, I wanted to make some changes on how routing would work and haven’t found anything in their docs about that.


I didn’t have Python installed on my laptop at the start, so setting up everything and having this demo up and running took me about a day, including hosting the demo. I figure it would be way faster for avid Python developers!

For further exploration, I think Wagtail could be a great headless CMS, especially with their built-in API. I think it could be cool to leverage it and strap it to tools like Nuxt or Gatsby to handle the front end.


By : Charles Ouellet
























What's Python IDLE? How to use Python IDLE to interact with Python?

What's Python IDLE? How to use Python IDLE to interact with Python?

In this tutorial, you’ll learn all the basics of using **IDLE** to write Python programs. You'll know what Python IDLE is and how you can use it to interact with Python directly. You’ve also learned how to work with Python files and customize Python IDLE to your liking.

In this tutorial, you'll learn how to use the development environment included with your Python installation. Python IDLE is a small program that packs a big punch! You'll learn how to use Python IDLE to interact with Python directly, work with Python files, and improve your development workflow.

If you’ve recently downloaded Python onto your computer, then you may have noticed a new program on your machine called IDLE. You might be wondering, “What is this program doing on my computer? I didn’t download that!” While you may not have downloaded this program on your own, IDLE comes bundled with every Python installation. It’s there to help you get started with the language right out of the box. In this tutorial, you’ll learn how to work in Python IDLE and a few cool tricks you can use on your Python journey!

In this tutorial, you’ll learn:

  • What Python IDLE is
  • How to interact with Python directly using IDLE
  • How to edit, execute, and debug Python files with IDLE
  • How to customize Python IDLE to your liking

Table of Contents

What Is Python IDLE?

Every Python installation comes with an Integrated Development and Learning Environment, which you’ll see shortened to IDLE or even IDE. These are a class of applications that help you write code more efficiently. While there are many IDEs for you to choose from, Python IDLE is very bare-bones, which makes it the perfect tool for a beginning programmer.

Python IDLE comes included in Python installations on Windows and Mac. If you’re a Linux user, then you should be able to find and download Python IDLE using your package manager. Once you’ve installed it, you can then use Python IDLE as an interactive interpreter or as a file editor.

An Interactive Interpreter

The best place to experiment with Python code is in the interactive interpreter, otherwise known as a shell. The shell is a basic Read-Eval-Print Loop (REPL). It reads a Python statement, evaluates the result of that statement, and then prints the result on the screen. Then, it loops back to read the next statement.

The Python shell is an excellent place to experiment with small code snippets. You can access it through the terminal or command line app on your machine. You can simplify your workflow with Python IDLE, which will immediately start a Python shell when you open it.

A File Editor

Every programmer needs to be able to edit and save text files. Python programs are files with the .py extension that contain lines of Python code. Python IDLE gives you the ability to create and edit these files with ease.

Python IDLE also provides several useful features that you’ll see in professional IDEs, like basic syntax highlighting, code completion, and auto-indentation. Professional IDEs are more robust pieces of software and they have a steep learning curve. If you’re just beginning your Python programming journey, then Python IDLE is a great alternative!

How to Use the Python IDLE Shell

The shell is the default mode of operation for Python IDLE. When you click on the icon to open the program, the shell is the first thing that you see:

This is a blank Python interpreter window. You can use it to start interacting with Python immediately. You can test it out with a short line of code:

Here, you used print() to output the string "Hello, from IDLE!" to your screen. This is the most basic way to interact with Python IDLE. You type in commands one at a time and Python responds with the result of each command.

Next, take a look at the menu bar. You’ll see a few options for using the shell:

You can restart the shell from this menu. If you select that option, then you’ll clear the state of the shell. It will act as though you’ve started a fresh instance of Python IDLE. The shell will forget about everything from its previous state:

In the image above, you first declare a variable, x = 5. When you call print(x), the shell shows the correct output, which is the number 5. However, when you restart the shell and try to call print(x) again, you can see that the shell prints a traceback. This is an error message that says the variable x is not defined. The shell has forgotten about everything that came before it was restarted.

You can also interrupt the execution of the shell from this menu. This will stop any program or statement that’s running in the shell at the time of interruption. Take a look at what happens when you send a keyboard interrupt to the shell:

A KeyboardInterrupt error message is displayed in red text at the bottom of your window. The program received the interrupt and has stopped executing.

How to Work With Python Files

Python IDLE offers a full-fledged file editor, which gives you the ability to write and execute Python programs from within this program. The built-in file editor also includes several features, like code completion and automatic indentation, that will speed up your coding workflow. First, let’s take a look at how to write and execute programs in Python IDLE.

Opening a File

To start a new Python file, select File → New File from the menu bar. This will open a blank file in the editor, like this:

From this window, you can write a brand new Python file. You can also open an existing Python file by selecting File → Open… in the menu bar. This will bring up your operating system’s file browser. Then, you can find the Python file you want to open.

If you’re interested in reading the source code for a Python module, then you can select File → Path Browser. This will let you view the modules that Python IDLE can see. When you double click on one, the file editor will open up and you’ll be able to read it.

The content of this window will be the same as the paths that are returned when you call sys.path. If you know the name of a specific module you want to view, then you can select File → Module Browser and type in the name of the module in the box that appears.

Editing a File

Once you’ve opened a file in Python IDLE, you can then make changes to it. When you’re ready to edit a file, you’ll see something like this:

The contents of your file are displayed in the open window. The bar along the top of the window contains three pieces of important information:

  1. The name of the file that you’re editing
  2. The full path to the folder where you can find this file on your computer
  3. The version of Python that IDLE is using

In the image above, you’re editing the file myFile.py, which is located in the Documents folder. The Python version is 3.7.1, which you can see in parentheses.

There are also two numbers in the bottom right corner of the window:

  1. Ln: shows the line number that your cursor is on.
  2. Col: shows the column number that your cursor is on.

It’s useful to see these numbers so that you can find errors more quickly. They also help you make sure that you’re staying within a certain line width.

There are a few visual cues in this window that will help you remember to save your work. If you look closely, then you’ll see that Python IDLE uses asterisks to let you know that your file has unsaved changes:

The file name shown in the top of the IDLE window is surrounded by asterisks. This means that there are unsaved changes in your editor. You can save these changes with your system’s standard keyboard shortcut, or you can select File → Save from the menu bar. Make sure that you save your file with the .py extension so that syntax highlighting will be enabled.

Executing a File

When you want to execute a file that you’ve created in IDLE, you should first make sure that it’s saved. Remember, you can see if your file is properly saved by looking for asterisks around the filename at the top of the file editor window. Don’t worry if you forget, though! Python IDLE will remind you to save whenever you attempt to execute an unsaved file.

To execute a file in IDLE, simply press the F5 key on your keyboard. You can also select Run → Run Module from the menu bar. Either option will restart the Python interpreter and then run the code that you’ve written with a fresh interpreter. The process is the same as when you run python3 -i [filename] in your terminal.

When your code is done executing, the interpreter will know everything about your code, including any global variables, functions, and classes. This makes Python IDLE a great place to inspect your data if something goes wrong. If you ever need to interrupt the execution of your program, then you can press Ctrl+C in the interpreter that’s running your code.

How to Improve Your Workflow

Now that you’ve seen how to write, edit, and execute files in Python IDLE, it’s time to speed up your workflow! The Python IDLE editor offers a few features that you’ll see in most professional IDEs to help you code faster. These features include automatic indentation, code completion and call tips, and code context.

Automatic Indentation

IDLE will automatically indent your code when it needs to start a new block. This usually happens after you type a colon (:). When you hit the enter key after the colon, your cursor will automatically move over a certain number of spaces and begin a new code block.

You can configure how many spaces the cursor will move in the settings, but the default is the standard four spaces. The developers of Python agreed on a standard style for well-written Python code, and this includes rules on indentation, whitespace, and more. This standard style was formalized and is now known as PEP 8. To learn more about it, check out How to Write Beautiful Python Code With PEP 8.

Code Completion and Call Tips

When you’re writing code for a large project or a complicated problem, you can spend a lot of time just typing out all of the code you need. Code completion helps you save typing time by trying to finish your code for you. Python IDLE has basic code completion functionality. It can only autocomplete the names of functions and classes. To use autocompletion in the editor, just press the tab key after a sequence of text.

Python IDLE will also provide call tips. A call tip is like a hint for a certain part of your code to help you remember what that element needs. After you type the left parenthesis to begin a function call, a call tip will appear if you don’t type anything for a few seconds. For example, if you can’t quite remember how to append to a list, then you can pause after the opening parenthesis to bring up the call tip:

The call tip will display as a popup note, reminding you how to append to a list. Call tips like these provide useful information as you’re writing code.

Code Context

The code context functionality is a neat feature of the Python IDLE file editor. It will show you the scope of a function, class, loop, or other construct. This is particularly useful when you’re scrolling through a lengthy file and need to keep track of where you are while reviewing code in the editor.

To turn it on, select Options → Code Context in the menu bar. You’ll see a gray bar appear at the top of the editor window:

As you scroll down through your code, the context that contains each line of code will stay inside of this gray bar. This means that the print() functions you see in the image above are a part of a main function. When you reach a line that’s outside the scope of this function, the bar will disappear.

How to Debug in IDLE

A bug is an unexpected problem in your program. They can appear in many forms, and some are more difficult to fix than others. Some bugs are tricky enough that you won’t be able to catch them by just reading through your program. Luckily, Python IDLE provides some basic tools that will help you debug your programs with ease!

Interpreter DEBUG Mode

If you want to run your code with the built-in debugger, then you’ll need to turn this feature on. To do so, select Debug → Debugger from the Python IDLE menu bar. In the interpreter, you should see [DEBUG ON] appear just before the prompt (>>>), which means the interpreter is ready and waiting.

When you execute your Python file, the debugger window will appear:

In this window, you can inspect the values of your local and global variables as your code executes. This gives you insight into how your data is being manipulated as your code runs.

You can also click the following buttons to move through your code:

  • Go: Press this to advance execution to the next breakpoint. You’ll learn about these in the next section.
  • Step: Press this to execute the current line and go to the next one.
  • Over: If the current line of code contains a function call, then press this to step over that function. In other words, execute that function and go to the next line, but don’t pause while executing the function (unless there is a breakpoint).
  • Out: If the current line of code is in a function, then press this to step out of this function. In other words, continue the execution of this function until you return from it.

Be careful, because there is no reverse button! You can only step forward in time through your program’s execution.

You’ll also see four checkboxes in the debug window:

  1. Globals: your program’s global information
  2. Locals: your program’s local information during execution
  3. Stack: the functions that run during execution
  4. Source: your file in the IDLE editor

When you select one of these, you’ll see the relevant information in your debug window.

Breakpoints

A breakpoint is a line of code that you’ve identified as a place where the interpreter should pause while running your code. They will only work when DEBUG mode is turned on, so make sure that you’ve done that first.

To set a breakpoint, right-click on the line of code that you wish to pause. This will highlight the line of code in yellow as a visual indication of a set breakpoint. You can set as many breakpoints in your code as you like. To undo a breakpoint, right-click the same line again and select Clear Breakpoint.

Once you’ve set your breakpoints and turned on DEBUG mode, you can run your code as you would normally. The debugger window will pop up, and you can start stepping through your code manually.

Errors and Exceptions

When you see an error reported to you in the interpreter, Python IDLE lets you jump right to the offending file or line from the menu bar. All you have to do is highlight the reported line number or file name with your cursor and select Debug → Go to file/line from the menu bar. This is will open up the offending file and take you to the line that contains the error. This feature works regardless of whether or not DEBUG mode is turned on.

Python IDLE also provides a tool called a stack viewer. You can access it under the Debug option in the menu bar. This tool will show you the traceback of an error as it appears on the stack of the last error or exception that Python IDLE encountered while running your code. When an unexpected or interesting error occurs, you might find it helpful to take a look at the stack. Otherwise, this feature can be difficult to parse and likely won’t be useful to you unless you’re writing very complicated code.

How to Customize Python IDLE

There are many ways that you can give Python IDLE a visual style that suits you. The default look and feel is based on the colors in the Python logo. If you don’t like how anything looks, then you can almost always change it.

To access the customization window, select Options → Configure IDLE from the menu bar. To preview the result of a change you want to make, press Apply. When you’re done customizing Python IDLE, press OK to save all of your changes. If you don’t want to save your changes, then simply press Cancel.

There are 5 areas of Python IDLE that you can customize:

  1. Fonts/Tabs
  2. Highlights
  3. Keys
  4. General
  5. Extensions

Let’s take a look at each of them now.

Fonts/Tabs

The first tab allows you to change things like font color, font size, and font style. You can change the font to almost any style you like, depending on what’s available for your operating system. The font settings window looks like this:

You can use the scrolling window to select which font you prefer. (I recommend you select a fixed-width font like Courier New.) Pick a font size that’s large enough for you to see well. You can also click the checkbox next to Bold to toggle whether or not all text appears in bold.

This window will also let you change how many spaces are used for each indentation level. By default, this will be set to the PEP 8 standard of four spaces. You can change this to make the width of your code more or less spread out to your liking.

Highlights

The second customization tab will let you change highlights. Syntax highlighting is an important feature of any IDE that highlights the syntax of the language that you’re working in. This helps you visually distinguish between the different Python constructs and the data used in your code.

Python IDLE allows you to fully customize the appearance of your Python code. It comes pre-installed with three different highlight themes:

  1. IDLE Day
  2. IDLE Night
  3. IDLE New

You can select from these pre-installed themes or create your own custom theme right in this window:

Unfortunately, IDLE does not allow you to install custom themes from a file. You have to create customs theme from this window. To do so, you can simply start changing the colors for different items. Select an item, and then press Choose color for. You’ll be brought to a color picker, where you can select the exact color that you want to use.

You’ll then be prompted to save this theme as a new custom theme, and you can enter a name of your choosing. You can then continue changing the colors of different items if you’d like. Remember to press Apply to see your changes in action!

Keys

The third customization tab lets you map different key presses to actions, also known as keyboard shortcuts. These are a vital component of your productivity whenever you use an IDE. You can either come up with your own keyboard shortcuts, or you can use the ones that come with IDLE. The pre-installed shortcuts are a good place to start:

The keyboard shortcuts are listed in alphabetical order by action. They’re listed in the format Action - Shortcut, where Action is what will happen when you press the key combination in Shortcut. If you want to use a built-in key set, then select a mapping that matches your operating system. Pay close attention to the different keys and make sure your keyboard has them!

Creating Your Own Shortcuts

The customization of the keyboard shortcuts is very similar to the customization of syntax highlighting colors. Unfortunately, IDLE does not allow you to install custom keyboard shortcuts from a file. You must create a custom set of shortcuts from the Keys tab.

Select one pair from the list and press Get New Keys for Selection. A new window will pop up:

Here, you can use the checkboxes and scrolling menu to select the combination of keys that you want to use for this shortcut. You can select Advanced Key Binding Entry >> to manually type in a command. Note that this cannot pick up the keys you press. You have to literally type in the command as you see it displayed to you in the list of shortcuts.

General

The fourth tab of the customization window is a place for small, general changes. The general settings tab looks like this:

Here, you can customize things like the window size and whether the shell or the file editor opens first when you start Python IDLE. Most of the things in this window are not that exciting to change, so you probably won’t need to fiddle with them much.

Extensions

The fifth tab of the customization window lets you add extensions to Python IDLE. Extensions allow you to add new, awesome features to the editor and the interpreter window. You can download them from the internet and install them to right into Python IDLE.

To view what extensions are installed, select Options → Configure IDLE -> Extensions. There are many extensions available on the internet for you to read more about. Find the ones you like and add them to Python IDLE!

Conclusion

In this tutorial, you’ve learned all the basics of using IDLE to write Python programs. You know what Python IDLE is and how you can use it to interact with Python directly. You’ve also learned how to work with Python files and customize Python IDLE to your liking.

You’ve learned how to:

  • Work with the Python IDLE shell
  • Use Python IDLE as a file editor
  • Improve your workflow with features to help you code faster
  • Debug your code and view errors and exceptions
  • Customize Python IDLE to your liking

Now you’re armed with a new tool that will let you productively write Pythonic code and save you countless hours down the road. Happy programming!

Importance of Python Programming skills

Importance of Python Programming skills

Python is one among the most easiest and user friendly programming languages when it comes to the field of software engineering. The codes and syntaxes of python is so simple and easy to use that it can be deployed in any problem solving...

Python is one among the most easiest and user friendly programming languages when it comes to the field of software engineering. The codes and syntaxes of python is so simple and easy to use that it can be deployed in any problem solving challenges. The codes of Python can easily be deployed in Data Science and Machine Learning. Due to this ease of deployment and easier syntaxes, this platform has a lot of real world problem solving applications. According to the sources the companies are eagerly hunting for the professionals with python skills along with SQL. An average python developer in the united states makes around 1 lakh U.S Dollars per annum. In some of the top IT hubs in our country like Bangalore, the demand for professionals in the domains of Data Science and Python Programming has surpassed over the past few years. As a result of which a lot of various python certification courses are available right now.

Array in Python: An array is defined as a data structure that can hold a fixed number of elements that are of the same python data type. The following are some of the basic functions of array in python:

  1. To find the transverse
  2. For insertion of the elements
  3. For deletion of the elements
  4. For searching the elements

Along with this one can easily crack any python interview by means of python interview questions

Tkinter Python Tutorial | Python GUI Programming Using Tkinter Tutorial | Python Training

This video on Tkinter tutorial covers all the basic aspects of creating and making use of your own simple Graphical User Interface (GUI) using Python. It establishes all of the concepts needed to get started with building your own user interfaces while coding in Python.

This video on Tkinter tutorial covers all the basic aspects of creating and making use of your own simple Graphical User Interface (GUI) using Python. It establishes all of the concepts needed to get started with building your own user interfaces while coding in Python.

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Original video source: https://www.youtube.com/watch?v=VMP1oQOxfM0