20240626_python_course.md

---
date: 2024-06-10
draft: True
authors: [gabrielbdornas]
comments: true
categories:
  - Python
  - Python course
---

# Python course - Class 1

Have you ever wanted to unlock the power of Python?
This versatile language is used by data scientists, web developers, and even hobbyists to automate tasks, analyze information, and build incredible applications.

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This content is designed to take you from absolute beginner to Python pro, guiding you step-by-step through the fundamentals and helping you put your newfound skills to the test with exciting projects.
Get ready to join the thriving Python community, let's get started!


## Instalations

- If you are using linux or mac it may be installed. Open your terminal and run `python --version`.
- If you are in Windows download it from [Python downloads page](https://www.python.org/downloads/).
- Download a text editor as [vs code](https://code.visualstudio.com/download) or [sublime text](https://www.sublimetext.com/3)
- If you are in Window download [git for windows](https://git-scm.com/download/win) as we'll need a terminal to run our programs.

## Your first Python program

- Here is your first Python program:

    ```python exec="1" source="tabbed-left" result="ini"
    print("Gabriel Braico Dornas") # (1)!
    ```

    1. :man_raising_hand: Run it using the [Python interpreter](https://docs.python.org/3/tutorial/interpreter.html) and/or `app.py` file.

- The program is executed line by line.

    ```python exec="1" source="tabbed-left" result="ini"
    print("o----") # (1)!
    print(" ||||")
    ```

    1. :man_raising_hand: Here, `o----` is a string (`str`) or a series of characters.


- String multiplication:

    ```python
    print('*' * 10) # (1)!
    ```

    1. :man_raising_hand: The `'*' * 10` is an expression, or a piece of code that produces a value. Python first evaluate the `'*' * 10` code and than it prints its result (`**********`).

??? question "What other shapes could we draw using string multiplication?"

    - Left-sided pyramid [^1]:

    ```python
    print('*')
    print('*' * 2)
    print('*' * 3)
    print('*' * 4)
    print('*' * 5)
    print('*' * 6)
    print('*' * 7)
    print('*' * 8)
    print('*' * 9)
    ```

    - Upside down pyramid [^1]:

    ```python
    print('*' * 9)
    print('*' * 8)
    print('*' * 7)
    print('*' * 6)
    print('*' * 5)
    print('*' * 4)
    print('*' * 3)
    print('*' * 2)
    print('*')
    ```

    ```python
    # Your turn!!
    ```

## Variables

- Variables temporarily stores data in a computer's memory:

    ```python
    price = 10  # (1)!
    print(price) # (2)!
    ```

    1. :man_raising_hand: Identifier (variable's name) + equal sign + variable's value.
    2. :man_raising_hand: Do not add quotations here.

- Update the variable's value:

    - Numbers variables:

        ```python
        price = 10 # (1)!
        price = 20
        print(price)
        rating = 4.6 # (2)!
        print(rating) # (3)!
        ```

        1. :man_raising_hand: Here, `10` is an integer (`int`) or a whole number without a decimal point.
        2. :man_raising_hand: Here, `4.6`  is a float (`float`) or a number with a decimal point.
        3. :man_raising_hand: Remember that the program is executed line by line.

    - Strings and booleans variables:

        ```python
        name = 'Gabriel Braico Dornas'
        print(name)
        is_approved = True # (1)!
        print(is_approved)
        ```

        1. :man_raising_hand: Here, `is_approved` is a boolean or as we say yes (`True`) and no (`False`). **Note that python is a case-sensitive language**.

    - Mix them:

        ```python
        my_variable = 2 # (1)!
        my_variable = 2.5 # (2)!
        my_variable = 'Gabriel Braico Dornas' # (3)!
        my_variable = False # (4)!
        print(my_variable) # (5)!
        ```

        1. :man_raising_hand: If `print(my_variable)` is added after here, it'll print the value `2`.
        2. :man_raising_hand: If `print(my_variable)` is added after here, it'll print the value `2.5`.
        3. :man_raising_hand: If `print(my_variable)` is added after here, it'll print the value `Gabriel Braico Dornas`.
        4. :man_raising_hand: As `print(my_variable)` was added after here, it'll print the value `False`.
        5. :man_raising_hand: Remember that the program is executed line by line.

??? question "Define variables to our new hospital program"

    - We check in a patient named John Smith. He's 20 years old and is a new patient. Define a variable to store the patient name, age and wheter it is a new patient or not.

    ??? "Give it a try before see my solution."

        ```python
        name = 'John Smith'
        age = 20
        is_new_patient = True
        print(name, age, is_new_patient) # (1)!
        ```

        1. :man_raising_hand: You can pass more them one value to be printed with the `print()` function.

## Receiving input

- Ask the user's name:

    ```python
    input('What is your name? ') # (1)!
    ```

    1. :man_raising_hand: Both the `print()` and the `input()` are functions built into Python. Think functions as the buttons in the remote control of your TV. The control's buttons are just like functions/operations that you can use over and over again. Function's parenthesis indicates that we are **calling** that function, or pressing a button on a remote control.

- Printing a nice message to our user:

    ```python
    name = input('What is your name? ') # (1)!
    print('Hi ' + name) # (2)!
    ```

    1. :man_raising_hand: Pay attention to the space after the question mark.
    2. :man_raising_hand: Another example of an expression, or a piece of code that produces a value.

??? question "What is your user's favorite color?"

    - As two questions to your user: His/her name and his/her favorite color. Then print a message like "Gabriel likes green!".

    ??? "Give it a try before see my solution."

        ```python
        name = input('What is your name? ')
        color = input('What is your favorite color? ')
        print(name + ' likes ' + color) # (1)!
        ```

        1. :man_raising_hand: As whe see, `print(name, 'likes', color)` will work as well. Type `help(print)` in [Python interpreter](https://docs.python.org/3/tutorial/interpreter.html) to understand why we don't need to use spaces in the "likes" `string` whith this approach.



[^1]: Idea from the [Creating Patterns in Python Medium post](https://mardiyyah.medium.com/creating-patterns-in-python-learnpythonthroughprojects-series-7-3e78db1b3a04).