Alayna  Rippin

Alayna Rippin

1614147300

How to Use Layers with Lambda Functions?

In this video we look at how to use layers with AWS Lambda functions. (with nodejs)

We look at a demo app which uses two npm modules (axios and image-size) which were installed using npm and are part of the bundle. We then extract these modules into a layer. We attach this layer to our function and import and use the modules we extracted.

It has 2 advantages:

  • it reduces the size of the bundle
  • it makes it possible to re-use the extracted code across several functions.

We also look at how to separate local files and extract them into a layer and then import them from the function.

#aws

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How to Use Layers with Lambda Functions?
Ray  Patel

Ray Patel

1619510796

Lambda, Map, Filter functions in python

Welcome to my Blog, In this article, we will learn python lambda function, Map function, and filter function.

Lambda function in python: Lambda is a one line anonymous function and lambda takes any number of arguments but can only have one expression and python lambda syntax is

Syntax: x = lambda arguments : expression

Now i will show you some python lambda function examples:

#python #anonymous function python #filter function in python #lambda #lambda python 3 #map python #python filter #python filter lambda #python lambda #python lambda examples #python map

PANDAS: Most Used Functions in Data Science

Most useful functions for data preprocessing

When you get introduced to machine learning, the first step is to learn Python and the basic step of learning Python is to learn pandas library. We can install pandas library by pip install pandas. After installing we have to import pandas each time of the running session. The data used for example is from the UCI repository “https://archive.ics.uci.edu/ml/datasets/Heart+failure+clinical+records

  1. Read Data

2. Head and Tail

3. Shape, Size and Info

4. isna

#pandas: most used functions in data science #pandas #data science #function #used python data #most used functions in data science

Why Use WordPress? What Can You Do With WordPress?

Can you use WordPress for anything other than blogging? To your surprise, yes. WordPress is more than just a blogging tool, and it has helped thousands of websites and web applications to thrive. The use of WordPress powers around 40% of online projects, and today in our blog, we would visit some amazing uses of WordPress other than blogging.
What Is The Use Of WordPress?

WordPress is the most popular website platform in the world. It is the first choice of businesses that want to set a feature-rich and dynamic Content Management System. So, if you ask what WordPress is used for, the answer is – everything. It is a super-flexible, feature-rich and secure platform that offers everything to build unique websites and applications. Let’s start knowing them:

1. Multiple Websites Under A Single Installation
WordPress Multisite allows you to develop multiple sites from a single WordPress installation. You can download WordPress and start building websites you want to launch under a single server. Literally speaking, you can handle hundreds of sites from one single dashboard, which now needs applause.
It is a highly efficient platform that allows you to easily run several websites under the same login credentials. One of the best things about WordPress is the themes it has to offer. You can simply download them and plugin for various sites and save space on sites without losing their speed.

2. WordPress Social Network
WordPress can be used for high-end projects such as Social Media Network. If you don’t have the money and patience to hire a coder and invest months in building a feature-rich social media site, go for WordPress. It is one of the most amazing uses of WordPress. Its stunning CMS is unbeatable. And you can build sites as good as Facebook or Reddit etc. It can just make the process a lot easier.
To set up a social media network, you would have to download a WordPress Plugin called BuddyPress. It would allow you to connect a community page with ease and would provide all the necessary features of a community or social media. It has direct messaging, activity stream, user groups, extended profiles, and so much more. You just have to download and configure it.
If BuddyPress doesn’t meet all your needs, don’t give up on your dreams. You can try out WP Symposium or PeepSo. There are also several themes you can use to build a social network.

3. Create A Forum For Your Brand’s Community
Communities are very important for your business. They help you stay in constant connection with your users and consumers. And allow you to turn them into a loyal customer base. Meanwhile, there are many good technologies that can be used for building a community page – the good old WordPress is still the best.
It is the best community development technology. If you want to build your online community, you need to consider all the amazing features you get with WordPress. Plugins such as BB Press is an open-source, template-driven PHP/ MySQL forum software. It is very simple and doesn’t hamper the experience of the website.
Other tools such as wpFoRo and Asgaros Forum are equally good for creating a community blog. They are lightweight tools that are easy to manage and integrate with your WordPress site easily. However, there is only one tiny problem; you need to have some technical knowledge to build a WordPress Community blog page.

4. Shortcodes
Since we gave you a problem in the previous section, we would also give you a perfect solution for it. You might not know to code, but you have shortcodes. Shortcodes help you execute functions without having to code. It is an easy way to build an amazing website, add new features, customize plugins easily. They are short lines of code, and rather than memorizing multiple lines; you can have zero technical knowledge and start building a feature-rich website or application.
There are also plugins like Shortcoder, Shortcodes Ultimate, and the Basics available on WordPress that can be used, and you would not even have to remember the shortcodes.

5. Build Online Stores
If you still think about why to use WordPress, use it to build an online store. You can start selling your goods online and start selling. It is an affordable technology that helps you build a feature-rich eCommerce store with WordPress.
WooCommerce is an extension of WordPress and is one of the most used eCommerce solutions. WooCommerce holds a 28% share of the global market and is one of the best ways to set up an online store. It allows you to build user-friendly and professional online stores and has thousands of free and paid extensions. Moreover as an open-source platform, and you don’t have to pay for the license.
Apart from WooCommerce, there are Easy Digital Downloads, iThemes Exchange, Shopify eCommerce plugin, and so much more available.

6. Security Features
WordPress takes security very seriously. It offers tons of external solutions that help you in safeguarding your WordPress site. While there is no way to ensure 100% security, it provides regular updates with security patches and provides several plugins to help with backups, two-factor authorization, and more.
By choosing hosting providers like WP Engine, you can improve the security of the website. It helps in threat detection, manage patching and updates, and internal security audits for the customers, and so much more.

Read More

#use of wordpress #use wordpress for business website #use wordpress for website #what is use of wordpress #why use wordpress #why use wordpress to build a website

Vincent Lab

Vincent Lab

1605017502

The Difference Between Regular Functions and Arrow Functions in JavaScript

Other then the syntactical differences. The main difference is the way the this keyword behaves? In an arrow function, the this keyword remains the same throughout the life-cycle of the function and is always bound to the value of this in the closest non-arrow parent function. Arrow functions can never be constructor functions so they can never be invoked with the new keyword. And they can never have duplicate named parameters like a regular function not using strict mode.

Here are a few code examples to show you some of the differences
this.name = "Bob";

const person = {
name: “Jon”,

<span style="color: #008000">// Regular function</span>
func1: <span style="color: #0000ff">function</span> () {
    console.log(<span style="color: #0000ff">this</span>);
},

<span style="color: #008000">// Arrow function</span>
func2: () =&gt; {
    console.log(<span style="color: #0000ff">this</span>);
}

}

person.func1(); // Call the Regular function
// Output: {name:“Jon”, func1:[Function: func1], func2:[Function: func2]}

person.func2(); // Call the Arrow function
// Output: {name:“Bob”}

The new keyword with an arrow function
const person = (name) => console.log("Your name is " + name);
const bob = new person("Bob");
// Uncaught TypeError: person is not a constructor

If you want to see a visual presentation on the differences, then you can see the video below:

#arrow functions #javascript #regular functions #arrow functions vs normal functions #difference between functions and arrow functions

What Are Python Lambda Functions ?

Learning Python Takes Time

Traveling the road from rookie to Pythonista can take a while and varies from person to person. Most people start learning Python by reviewing the basic data structures for numbers, Booleans and strings, and then move to complex data structures like lists and dictionaries. From there you learn loops and if/else control logic, and eventually learn to write reusable code via functions.

Once you start exploring functions, you’ll come across lambda functions which can seem pretty intimidating at first. Similarly to list comprehensions, lambda functions allow you to write succinct code. Often something that would take several lines as a defined function can be done in one line using a lambda function!

Reviewing Python Functions

Typical Python functions are simply a self-contained set of instructions designed to perform a specific task. They are important to master and understand because they allow us to keep code organized by breaking it into smaller, reusable chunks. If we’re writing a large program, utilizing functions can make the code easier to read and debug too.

In Python, we define a function using the def keyword, then give the function a name along with any necessary arguments that impact the function body’s execution. Often times, the return keyword is used to terminate the function and return the desired output to whatever called the function. Here is an example function:

#python example function
def my_function(string):
     return print(string) 

testing my_function

The example my_function takes a string as an argument and prints the string as the returned output.

What Is A Lambda Function?

To take your Python skills to the next level, you need to master both normal functions and lambda functions. Lambda functions are great for making code shorter and more concise, which is the way of the Pythonista! We’ll take a look at a few simple examples to review the syntax, and then look at some actual use cases for lambda functions that will make you look like a pro.

As we see in the previous example, normal functions are defined using def and given a name. Lambda functions are defined using the lambda keyword and are nameless. They are anonymous functions that are not defined in any namespace, and they are intended for single use.

When I first learned about lambda functions, it seemed a bit tricky to wrap my head around. The syntax can feel confusing since a lambda function can take any number of arguments, but can only have one expression. Here are a couple simple examples:

#lambda syntax
#lambda <arguments> : <return expression>#simple example
lambda_example = lambda x: x + x#multiple arguments example
multiple_arguments = lambda x, y, z: (x + y) * z

Testing lambda function examples

Notice the multiple arguments are separated by commas. When calling the function, the caller provides the arguments. The return expression is defined after the colon (:). There is a single return expression, but the return expression can be simple or complex. It could even be another function, which makes lambda functions a powerful tool in your Python programming toolbox.

Using Lambda Functions

Let’s take a look at how we can use lambda to write functions the Pythonic way. Below we have a function that checks a list of strings for the word “two.” It returns the list of strings along with True or False depending on whether the word was in the strings:

sentences = ['Sentence one.', 'Sentence two.', 'Sentence three.']def contains_two(text):
    answers = []
    for s in txt:
        if 'two' in s:
            answers.append(True)
        else:
            answers.append(False)
    return zip(answers, text)

Testing contains_two function

Instead of defining a function and using a for loop to go through the list, we can rewrite this succinctly using Python’s map() function along with a lambda function.

contains_two_lambda = map(lambda x: (True, x) if 'two' in x else (False, x), sentences)

Testing contains_two_lambda function

The map() function takes a function and a sequence as arguments, running the function on the given sequence. The function we pass to map() is a lambda function, allowing us to perform the same thing our defined function does in only one line of code!

Lambda functions work well with functions like map(), reduce(), and filter(), three built-in Python functions that take a function as arguments. Lambda functions are also popular in data munging as they can work well with pandas dataframes. They can make applying logical operations to columns and rows concise one-liners.

Using Lambda Functions With Pandas DataFrames

As an analyst, I find myself using Pandas DataFrames all the time. Since DataFames are a popular data structure, let’s take a look at how easy it is to use lambda functions for transforming data in dataframes. Let’s create a simple pandas dataframe with some mock data:

#import dependencies
import pandas as pd#create dataframe
df = pd.DataFrame({
  'Occupation': ['Data Tech','Sales','Analyst','Engineer'],
  'Name': ['John Smith', 'Jodie Whales', 'Eric Kleppen', 'Richard Heart'],
  'Salary': [50000, 75000, 80000, 100000],
  'YearsAtCompany': [2, 3, 1, 3],})

Example dataframe

Next, let's create a new column called newSalary using a lambda function. If I’m giving out raises based on the column YearsAtCompany and want to see what a person’s new salary will be, I can use the apply() function similar to how we used map() in the previous example:

df['newSalary'] = 
df['Salary'].apply(lambda x: x * (1 + df['YearsAtCompany']/10))

Verifying newSalary column

Notice that the apply() function takes the lambda function as an argument and applies the function to each row in the Salary column. The expression in the lambda function uses YearsAtCompany to determine the size of the raise.

Wrapping Up

Writing Python like a pro takes practice, so don’t worry if you feel intimidated by new concepts like lambda functions. The syntax looks strange, but lambda functions allow you to write concise, one-time-use functions that are great for applying logical operations.

Although they can only perform one expression, the expression can be complex and even include another function. Lambda functions can work well with series of data, as even data structures like Pandas DataFrames. 

This story was originally published at https://betterprogramming.pub/become-a-python-programmer-what-are-lambda-functions-1de065686edf

#python #lambda #programmers