3. Functions without parameters

See: `<https://www.w3schools.com/python/python_functions.asp

Functions are blocks of code that can be used many times in a program.

They avoid code repetition.

Functions can do something or return values.

Functions are defined using the def keyword.

To use the function, it is called using its name with parentheses.

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3.1. Functions that do something

The function below does something. It scrolls text.

It is defined using the def keyword and has empty parentheses.

The def line has a colon at the end and the code for the definition is indented.

To use the function, it is called using its name with parentheses; show_welcome().

from microbit import *

def show_welcome():
    display.scroll("Hello mb user!", delay=80)

show_welcome()

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Tasks

1. Write a function called scroll_name that scrolls your name.

2. Write a function called countdown that counts down from 5 to 1, showing each number.

Q1

Write a function called scroll_name that scrolls your name.

from microbit import *

def scroll_name():
    display.scroll("my name", delay=80)

scroll_name()

Q2

Write a function called countdown that counts down from 5 to 1, showing each number.

from microbit import *

def countdown():
    for num in range(5, 0, -1):
        display.show(num)
        sleep(300)
    display.clear()

countdown()

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3.2. Functions that return a value

The function below returns a value.

It returns True when the microbit is tilted to the right enough, otherwise it returns False.

from microbit import *

def is_right_tilt():
    if accelerometer.get_x() > 300:
        return True
    else:
        return False

while True:
    display.scroll(is_right_tilt())
    sleep(500)

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Tasks

1. Write a function called is_left_tilt that returns True or False.

2. Write a function called is_cold that returns True when the temperature is below 20 Celsius, otherwise False.

3. Write a function called get_fahrenheit that returns the temperature in degress Fahrenheit.

Q1

Write a function called is_left_tilt that returns True or False.

from microbit import *

def is_left_tilt():
    if accelerometer.get_x() < -300:
        return True
    else:
        return False

while True:
    display.scroll(is_left_tilt())
    sleep(500)

Q2

Write a function called is_cold that returns True when the temperature is below 20 Celsius, otherwise False.

from microbit import *

def is_cold():
    if temperature() < 20:
        return True
    else:
        return False

while True:
    display.scroll(is_cold())
    sleep(500)

Q3

Write a function called get_fahrenheit that returns the temperature in degress Fahrenheit.

from microbit import *

def get_fahrenheit():
    celsius = temperature()
    fahrenheit = (celsius * 1.8) + 32
    return fahrenheit

while True:
    display.scroll(get_fahrenheit())
    sleep(500)