• # Where Pandas and Graphs gather to unveil some of their secrets!

Hello, checkiomates🐱‍👤!

It's Thursday, which we call the news day! As usual, we prepare three new missions to train your 🧠, where you will play with lists and "compress" integer to one digit!

We also provide you with links to some interesting topics. You are welcome to read and discuss them here under the news post. And of course use this information for solving missions!

Common Tail by freeman_lex - in which you are given two lists of integers. Your function should return an element, from what a common part starts and there are no different element(s) after this part - the first element of the last common part.

```common_tail([], [1, 2, 3]) == None
common_tail([1], [1]) == 1
common_tail([3], [1, 2, 3]) == 3```

Move Zeros by freeman_lex - you are given a list of integers here as well. Move all zeros in the list to the end of it. The order of non-zero elements should not change.

```move_zeros([0, 1, 0, 3, 12]) == [1, 3, 12, 0, 0]
move_zeros([0]) == [0]```

Sum of Digits by Doppelok - you are given an integer. If it consists of one digit, simply return its value. If it consists of two or more digits - add them until the number contains only one digit and return it.

```sum_digits(38) == 2
sum_digits(0) == 0
sum_digits(10) == 1```

💡Enlighten yourself with the new portion of python-related LINKS:

The Definitive Guide to Graph Problems - has a lot of information and examples about exploring graphs using two types of search and solving different specific problems. You will definitely use this knowledge at CheckiO, since we have mission with graphs!

Pandas Groupby Warning - this topic talks about a problem, that may occur while groupby-ing pandas data frame and how to solve it. Here I remind you that you are totally free to use some third-part modules in your solutions. We even have a dedicated category of solutions, where you may publish yours - "3rd party".

Fundamentals of object-oriented programming (OOP) - is a basic conceptual article of object-oriented programming. Fundamentals, composition, and behaviors.

🙌 See ya on some CheckiO island! 🏝

Welcome to CheckiO - games for coders where you can improve your codings skills.

The main idea behind these games is to give you the opportunity to learn by exchanging experience with the rest of the community. Every day we are trying to find interesting solutions for you to help you become a better coder.