0. Introduction and general info about course.md

Introduction and general info about course

About myself

• I have graduated at Faculty of Economics, University of Belgrade (2010-2015)

• After graduation I started to code

  • 2016-2018 mainly focused on Mathematica and Wolfram language

  • In 2018 I started to code in python

Work experience

• eFrond - Financial analyst

  • Main tool was Excel

• GroundLink - Data Scientist

  • Automation of web data collection

  • Collection and analysis of competitors prices

  • Main tools were Python and Selenium

• NCR - Big Data Developer

My teaching experience

• Selenium web-scraping introductory course held in late 2019 in GroundLink ( 5 colleagues attended training )

• Individual teaching - helping friends get start with python

Course background

• How everything started?

• How we ended up participating in this course?

About course

• This is course for absolute beginners

• No prior knowledge is assumed

• Pace is going to be easy and slow

Elements of programming

• Introduction to course

• IDE vs Command line

• Different levels of abstractions

• What is abstraction?

• Programming VS coding

• American VS Japanese philosophy

• Built-in functions

• User defined functions

• Collections (list, dictionary, tuple, set)

• Iteration over collection

• For VS while loop

• Exceptions

• Pandas DataFrame()

• Map, Apply, vectorised operations

• Nested collections, nested loops

• Variable scope: global VS local variables

• Mutability

• Classes and Objects

• Abstraction VS implementation

• Procedures

• Types of variables: basic(simple) VS compound(complex)

• Different ways to execute python program

• Programming VS programming language

Course structure

1. Variables, expressions, statements

2. Functions (builtin and user defined)

3. Control structures - Part I

4. Collections (lists, tuples, dictionaries, sets)

5. Control structures - Part II

6. Functional programming

7. Exceptions

8. Mutability of objects

9. Classes and objects

10. List comprehension

Course materials

• https://www.openbookproject.net/thinkcs/python/english2e/index.html#

• http://greenteapress.com/thinkpython2/html/index.html

Introduction

3 family of questions:

1. What are we going to learn? What is the topic? What question do we try to answer?

2. Why is it important? How can it help me? Why do I care? How can I benefit from it? What are its alternatives?

3. How to use it? How to implement it? What are different ways to apply it?

• If someone ask you what is programming, but give you only 10 seconds to answer…

• Everything is about data

  1. Getting data

  2. Transforming data

  3. Storing data

Where does name ‘Information technology’ comes from?

There is relationship: Data -> Information -> Knowledge

• Data - just any number, string or sequence of it

• Information - we know what data means

• Knowledge - we know how to use that information, how to take advantage and why it is important for us

How computers work

• Computers can do ONLY 3 things:

  • Perform calculation

  • Remember result

  • Decide weather to continue or stop execution

How humans work

Feynman technique:

1. Pick and study a topic

2. Explain the topic to someone, like a child, who is unfamiliar to the topic

3. Identify any gaps in your understanding

4. Review and simplify

Structured approach

What is structured approach?

You have clear understanding of:

• Things you want to achieve

• Sequence of steps you need to perform and

• You can, in simple words, explain your goal and way to achieve it

Why structured approach?

Main source of mistake in computer science:

• Things you want to achieve are not understood (you do not know to explain it in simple words)

• Assumptions

• Miscommunication

Learning strategy

Looking at things as elements of a whole

• What are important elements?

• What is relationship/hierarchy between elements?

Take difficult topic and split it apart into sequence of simple steps

Acceptable number of steps in a sequence

What does acceptable in this case mean?

• 3-5 cause-effect relationships

Top to bottom approach

• Start high level

• Go down into implementation details

Bottom up approach

• Start from (boring) implementation details

• Then, eventually, go to ‘why’ question

Top down approach

• View from top of the hill VS view from valley.

• Start from top of the hill and slowly go down to valley.

• Valley looks different when observed from top of the hill.

• Top of the hill picture give us broader perspective.

• Top of the hill = Generalisation.

Introduction to CS

• In computer science, at the beginning, we don’t know from where to start!

• There is no unique or best way from where to start journey.

• It is about journey, not final destination!

Dilemma

• Sometimes there are several ways to do same thing. Easy and hard way.

• Which one to show you first?

Learning strategy

• It is always good to have final goal in mind!

• How python is going to help me?

• When it is going to help me?

• What are potential use cases where I can apply it?

Everyone is different

Person A

• Figure out concept X in 3 minutes

• Needs 3 hours to figure out concept Y

Person B

• Figure out concept X in 3 hours

• Needs only 3 minutes to understand concept Y

Goals

• What are goals of python training?

  • To become good entry level programmer

• What are NOT goals of python training?

  • To make expert from you

Learning hack

• It is always better to know one thing very good, than to know many things partially.

Pandas and NumPy

• Pandas is most productive python library.

• This is not training for pandas and numpy.

• Hopefully, after we learn basics, there will be space for new course focused primarily on pandas.

• Pandas and NumPy are special languages built on top of python language.

• They have special syntax.

• Knowledge of python building blocks give us chance to figure out:

  • What can be source of error
  • What is not source of error

• Pandas is very useful and easy to use library.

  • In order to be easy to use, basic building blocks of python should be mastered first.

• Same story for NumPy.

Ask question !!!

• What questions are welcomed?

  • Why does it work this way?
  • For me, it is more logical other way around?
  • Why it doesn’t wort that way, but this way?
  • Why someone invented this?
  • How is it going to help me?

• This topic is difficult to master, it will took me lot of time and effort until I become comfortable with it.

• How is it going to help me?

• After I master it, how is it going to improve me as developer?

• What kind of business question I will be able to solve?

Useful Knowledge

• It is all about generalisation

• Rule 80 / 20

• Important VS Not-important

• Common VS Not-so-common

• Sth that you can apply on daily basis

• Sth that can make your life more meaningfull, productive and enjoyable.

Learning = experimentation

• Be encouraged to make mistakes!

• At the beginning, there is no excuse not to make mistakes!

• The more mistakes you make, the faster and better you learn.

Learning strategy

• Description, understanding and explanation differ based on level of general knowledge.

• It depends from which point of view we are looking at things.

• Sometimes, at the beginning we will define things in one way. While, later on, we will define same thing in another way.

• We will just be looking on same things from different point of view.

How to explain new things

• There is explanation that is good for someone who is just starting to learn new materials/ideas.

• There is explanation for someone who is expert in field, for someone who already know materials/ideas/concepts.

• Usually those two types of explanations differ radically!!!

Knowledge base

• I know what I know

• I know what I don’t know

• I don’t know what I don’t know

Two stage process

• Design: What we want to code? Sequence of simple steps.

• Implementation: coding, writing solution in particular programming language.

Abstraction

• When you hear some topic/concept/element, you know what is relevant to that, you know what is important regarding that.

• Eg. we introduced new concept, what other concepts/elements are important with regard to that one.

• What are similar things, what are not related topics.

Not good developer

• Someone who knows all syntax by heart

Excellent Developer

What does it mean to be good developer?

1. Strong knowledge of building blocks

2. Know how to implement new functions/classes that come from new libraries. Know how to read documentations.

Be curious!

• It is more difficult to ask good question than to answer it!

Syntax VS Semantic

• What is more important?

Learning workflow

• Repeat what you see in class, do homework. It will give you good knowledge of elementary concepts. (easier part)

• After you get knowledge of basic building blocks, pick a topic. Do pet projects. Experiment and apply what you learn in new areas and practical cases.

How I learn

• I enjoy in taking things apart ...

• ... and putting them back again.

Class Structure

• Part I

  • Listening about new concepts.

• Part II

  • Exercise. Practice what you learned.

Practice = making mistakes

• People are afraid of making mistakes.

• How can I encourage you to make mistakes?

• What should I do to motivate you to make mistakes?

Be ready !!!

• Familiarise yourself with Google

• Google is going to become your best friend

Good thing about programming

• You are never first person who asked that question.

• Someone has already asked question that you are interested in.

• You can always find how.

Be creative

• I will not teach you anything new

• I will just show you that you already know everything

• Ask questions

• Think what actions are on our disposal

• From what bundle of actions we can choose particular one?

• Think what is possible

• What can be solution?

• What kind of things could happen during the implementation?

• What kind of solution is going to satisfy you?

• What level of accuracy is going to make you happy?

• What is best case scenario? What is worst case scenario?

Python for everyone

• You can use python for many different things.
  • Web development
  • Data Science
  • Automated software testing etc.
• Often, people who use same tool (python in our case), and work in different areas of development, have different mindset and barely can understand each other.
• They are different animals :-)

About language syntax

• Syntax is very important. You will learn it along the way.

• Do not focus on syntax at the beginning.

Final goal of training

• Purpose of the course is to make self-learnable machines from you :)

• Goal is to be able to continue learning journey alone.

Sanity check type of questions

• Why I need it?
• How often I will encounter it?
• Is it necessary?

Learning strategy

• What programming elements exist?
  • This is what we are going to learn.
• How to combine them?
  • Requires logic and lot of creativity. We will just scratch it.

What we learned today?

• How to approach learning process

• How to behave on this journey

• What to expect

Plan for next session

• Installing python and IDEs.

• Getting familiar with tools we are going to use.

Think about!

• Project where you can use python to automate process
• Have you ever heard that someone used python for sth that you are interested in?
• How you can improve your daily tasks with python?

The end

• Thanks for your most valuable resource. Your time.