python

• Python

  One of the most popular programming languages, used for automation, AI, building applications and websites
• Python is for anyone who wants to learn it
• Mosh Hamedani


  Software engineer with two decades of experience, has taught over 3 million people how to code
• Installing Python


  1. Open browser, go to Python.org, click Downloads, download latest version, install

  2. Add Python to PATH (Windows)

  3. Run installer (Mac)
• Installing PyCharm


  Go to jetbrains.com/pycharm, download Community Edition, install
• Python 2 is considered legacy and no longer maintained
• Creating a new Python project in PyCharm

  Create new project, name it, ensure base interpreter is set to Python 3
• Writing first Python program

  Create new Python file, write print statement with name, run program
• Python code is executed line by line by the Python interpreter
• Drawing a dog using print statements


  Add additional print statements with ASCII art to draw a dog
• Expression


  A piece of code that produces a value
• It takes 9-12 months to become job-ready with Python, including learning a specialization like web development or machine learning
• Variable


  A way to temporarily store data in a computer's memory
• Integer


  A whole number without a decimal point
• Float


  A number with a decimal point
• Boolean


  A value that can be true or false
• Interpreter


  Executes our code line by line from the top
• Executing code


  1. Set the price to 10

  2. Reset it to 20

  3. Print it on the terminal
• Integers


  Numbers without a decimal point
• Floating point numbers/Floats


  Numbers with a decimal point
• Strings


  A sequence of characters
• Booleans


  Values that can be true or false
• Python is a case sensitive language
• Simple values that can be stored in Python

  • Numbers (integers or floats)
  • Strings
  • Booleans
• Variables


  Containers that store values in the computer's memory
• The input function is used to receive input from the user
• Receiving user input


  1. Print a message

  2. Wait for user to enter a value

  3. Store the value in a variable
• Concatenating strings


  Combines two strings into one
• Calculating age


  1. Get birth year from user

  2. Subtract birth year from current year (2019)

  3. Print the age
• The input function returns a string, even if the user enters a number
• int() function


  Converts a string to an integer
• Converting user input to integer

  1. Use int() function

  2. Perform calculation with integer value
• Converting weight in pounds to kilograms

  1. Get weight in pounds from user

  2. Multiply by 0.45 to convert to kilograms

  3. Print weight in kilograms
• Strings


  Sequences of characters that can be defined using single or double quotes
• Strings can contain apostrophes or double quotes if the string is defined using the opposite type of quote
• Triple quotes


  Used to define multi-line strings
• String indexing


  Characters in a string can be accessed by their index, starting from 0 for the first character. Negative indices can be used to access characters from the end of the string.
• Square brackets


  Used to get a character at a given index in a string
• In Python, strings are indexed starting from 0
• Negative indices can be used to access characters from the end of the string