x = 0.1
y = 0.2
print(x + y)  # 0.30000000000000004 

1. Я взяла когорты пользователей — зарегистрировавшихся с 1 Января по 31 Января 2020, c 1 Февраля по 29 Февраля и т.д. вплоть до Апреля. Посчитала LT в месяцах, предварительно выкинув пользователей 'проживших' один день. То есть внесших депозит и больше не появляющихся в какой-либо день за полгода.
2. Я брала всех пользователей, даже тех кто прожил 1 день и рассчитывала когорты по неделям среди всех, зарегистрировавшихся с 1 января по 29 февраля 2020 года.

Итак, 1-ый способ

Having a brilliant mobile app idea doesn’t mean that you will become successful tomorrow. The major component of its success is in the hands of mobile app developers. So it’s crucial to find a skilled team of engineers who will understand your plan and find the best way to bring it to life. If you are lost in a ton of mobile app development companies, this guide will help you avoid common pitfalls during the process of finding developers.

Selection Criteria

Portfolio

Look at the company’s portfolio, it is usually placed on their website. If there is no portfolio, the company is probably not trustworthy. While browsing the portfolio, find out if the company has expertise in technologies and industries similar to those you plan to go with. You are lucky if you also find a step-by-step description of their development process.

Client reviews

Analyze clients’ reviews and the company’s reaction to them. Reviews may be found by searching for “company_name reviews” or visiting popular review websites such

Are you looking for the top programming languages?

If yes, then your search ends here. If you are aspiring to become a programmer, then you must know some programming languages to stay ahead of the competition.

Various new programming languages are coming up with each passing year. Every beginner is puzzled up and looking at which programming languages they should learn.

As the software industry is changing, with every new release, it is a bit difficult to find the best programming language. You have to be careful while selecting programming languages, ​​as this will affect your career and job types.

So, here I have listed the top 10 Programming Languages you must know for future perspective.

This is a tutorial for creating a login system with the help of HTML, PHP, and MySQL. Your website needs to be dynamic and your visitors need to have instant access to it. Therefore, they want to log in as many times as possible. The login authentication system is very common for any web application. It allows registered users to access the website and members-only features. It is also helpful when we want to store information for users. It covers everything from shopping sites, educational sites, and membership sites, etc.

This tutorial is covered in 4 parts.

Table of Contents

1. Signup System
2. Login System
3. Welcome Page
4. Logout Script

1) Building a Signup system

In this part, We will create a signup system that allows users to create a new account to the system. Our first step is to create a HTML registration form. The form is pretty simple to create. It only asks for a name, email, password, and confirm password. Email addresses will be unique for every user. Multiple accounts for the same email address are not allowed. It will show an error message to the users who try to create multiple accounts with the same email address.

> abc
['abc', 'a.bc', 'ab.c', 'a.b.c']

00
01
10
11

In Python, List comprehension is a technique of creating a new list using other iterables and in fewer lines of codes. The iterable object which can be used in this technique can be any data structure like list, tuple, set, string, and dictionary, etc. An iterable created by using range() function can also be used here.

The syntax used in list comprehension generally contains three segments:

• iterable: iterable object like list, tuple, set, string, dictionary, etc.
• transformation function: a transformation function that needs to be applied to the iterable.
• filters: filters/conditions which are required to apply on iterable.

Syntax

#list comprehension syntax
list = [tranform_func(i) for i in iterable if filters]

#which is equivalent to...
for i in iterator:
  if filters:
    list.append(tranform_func(i))

Throughout the world, companies large and small alike are increasingly adding, expanding, and modernizing their electronic data interchange (EDI) communications. If you need to meet partner EDI mandates or wish to capture the many benefits afforded by EDI connectivity with more of your partners, you can take several approaches to EDI. Two of the most popular include value-added networks (VANs) and direct EDI (typically via AS2).

If you're new to EDI, you may be wondering what these options entail and which is right for your business. If you've been operating EDI for some time, you may be considering whether now is the time to switch. Let's dive in and explore the advantages and disadvantages of direct EDI with AS2 vs. VANs.

Microsoft Teams

• Good integration with Office 365
• Thread focused chat model
• Document collaboration

Buj

• Unified AI driven feed
• Searchable history
• Multiple conversations per post
• Audio, Video Calls & Screensharing

The significance of cross platform development is there for every one of us to see. In today’s business world, where a mobile app or a web app is a must to take your business to the next level, cross platform app development has become very popular, especially while building mobile apps.

1) What is Spring Boot?

2) List some features of Spring Boot?

1. Admin features
2. Application events and listeners
3. SpringApplication
4. Web Development

3) What are the advantages of Spring Boot?

4) What are the ways to create Spring Boot application using Maven?

With the accelerating pace of innovations in technology, it won’t be surprising to know that AI is briskly conquering the global economy and intelligently revolutionizing the face of businesses. From ordering your food, managing your work to gathering information from robots, Artificial Intelligence is powerfully transforming every move of your life, and organizations are not an exception.
Someone asked Alexa- How Could AI Impact My Business in 2020? Does it change the traditional outlook of my business? Is it essential to have a thought about chatbot development services?

And Alexa simply answered this question with the mindful saying of Stephen Hawking “Computers will overtake humans with AI within the next 100years. When that happens, we need to make sure the computers have goals aligned with ours".

• A search report forecast that, in America, voice-assistant devices have been increased to 129% from last year.
• According to the survey, AI global market is projected to grow up to a value of $89.9 billion by 2025.
• In 2018, 29% of the task of the top 12 industries was handled by AI-driven machines and encouraged automation in the business.
  
  
• 61% of professionals are considering Machine Learning and Artificial Intelligence as their company's most part of their growth.
• 80% of business leaders have concluded that AI boosts productivity and create better growth opportunities.

Microsoft has created the SQL Server that is a relational database management system. The primary functionality of SQL is to store and recover the information as mentioned by the client or another application. SQL functions can either run on a similar framework or another over a system. In this tutorial, things are explained like,

• Download Microsoft SQL Server
• Installation of SQL Server