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TASK 3

Assignment

So, you cannot put something that is the wrong datatype into a variable.

However, you can replace what is stored by the variable with another value of the same dataype.

So, say we have a variable:

x : int = 5

And then, we decide to store a different value:

x = 6

Now the variable has 6 inside, notice that we didn't have to say the datatype? This is because the computer already has an integer-shaped box called x, this just tells the computer to replace what is inside the box

We call this Assignment

In the following task, we have created a variable with the identifier x and intitally set it's value to 10.

Your task is to assign a new value to x, anything that isn't 10. However, you must do so after the print statement using an assignment!

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GUIDE

This guide is intended to help with syntax. See the prelude section for pre-defined functions and variables. See the tutorials page for tutorials on how to write code.

• Data Types

  • int

    int

    Integer values, such as 2, -4 and 254.

  • float

    float

    Floating point values, such as 2.0, -4.72 and 254.2681.

  • string

    string

    String values, such as "hello, world!", "haha" and "33".

  • boolean

    boolean

    Boolean values True and False.

  • colour

    colour

    Colour values for drawing on the canvase, See the prelude for more.

  • list

    list[element_type]

    List values. Note the element type must be correctly specified. Examples are [1,2,3], [["hello"], ["world"]] and [].

• Variables

  • declaration

    name: type

    A variable must first be declared with a type before it can be used

  • assignment

    name = value

  • increment

    name += value

    Only applicable to integer values. Equivalent to name = name + value .

  • decrement

    name -= value

    Only applicable to integer values. Equivalent to name = name - value .

• Expressions

  • logic

    Applicable to boolean values. and, or and not.

  • mathematical

    Applicable to numerical values. +, -, *, **, /, // and %.

  • relational

    Applicable to comparable values. >, <, ==, !=, <= and >=.

• Selection Statements

  • if

    if condition: statements elif condition: statements else: statements

• Loops

  • while

    while condition: statements

  • for

    for ident in list: statements

• Function

  • function

    def name(parameter: parameter_type) -> return_type: statements

    Values can be returned with return

  • procedure

    def name(parameter: parameter_type): statements

    Equivalent to a function which returns a None type

Can't find what you're looking for?

Check the tutorials page for more!

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PRELUDE

The prelude is all the pre-defined functions and variables available to use. See the tutorials page for tutorials on how to write code.

• Terminal Functions

  • print

    print(expr)

    Prints the value of the expression to the terminal.

  • print_str

    print_str(expr)

    Prints the value of the expression as a string to the terminal.

  • clear_terminal

    clear_terminal()

    Clears the terminal.

  • input

    input(message: str) -> str

    Displays message to the user, and returns their input as a string.

• Type Functions

  • str

    str(expr) -> str

    Where possible returns the string representation of expr.

  • int

    int(expr) -> int

    Where possible parses the integer representation of expr.

  • float

    float(expr) -> float

    Where possible parses the float representation of expr.

  • len

    len(expr) -> int

    Where possible returns the length of expr.

  • type

    type(expr) -> str

    Returns the name of the type of expr.

• Math Functions

  • round

    round(n: float) -> int

    Rounds the value of n using bankers rounding.

  • random_int

    random_int(from: int, to: int) -> int

    Returns a random integer between from and to.

  • random_float

    random_float(from: float, to: float) -> float

    Returns a random float between from and to.

  • pi

    pi: int

    The value of π.

• String Functions

  • upper

    str.upper()

    Returns the uppercase of str.

  • lower

    str.lower()

    Returns the lowercase of str.

  • replace

    str.replace(s1: str, s2: str)

    Returns a string will all occurances of s1 replaced with s2.

  • split

    str.split(d: str)

    Returns a list of strings of str split on all occurances of d.

  • join

    str.join(ss: list[str])

    Returns a string from joining all strings in ss using d.

  • isnumeric

    str.isnumeric() -> bool

    Returns true if all characters in str are numbers.

• List Functions

  • append

    l.append(elem)

    Appends elem to the list l.

  • remove

    l.remove(elem)

    Removes the first instance of elem from the list l.

  • count

    l.count(elem)

    Returns the total of elems present in the list l.

  • range

    range(f: int, t: int) -> list[int]

    Returns the list of values from f to t.

• Drawing Functions

  • line

    line(x1: int, y1: int, x2: int, y2: int)

    Draws a line from (x1,y1) to (x2,y2).

  • rect

    rect(x: int, y: int, w: int, h: int)

    Draws a rectangle of dimensions w by h on the canvas at position (x,y).

  • circle

    circle(x: int, y: int, r: int)

    Draws a circle with radius r on the canvas at position (x,y).

  • ellipse

    ellipse(x: int, y: int, r1: int, r2: int)

    Draws an ellispe with horizontal radius r1 and vertical radius r2 at position (x,y).

  • arc

    arc(x: int, y: int, r: int, f: int, t: int)

    Draws an arc with radius r on the canvas at position (x,y) from f degrees to t degrees.

  • sect

    sect(x: int, y: int, r: int, f: int, t: int)

    Draws a sector with radius r on the canvas at position (x,y) from f degrees to t degrees.

  • triangle

    triangle(x1: int, y1: int, x2: int, y2: int, x3: int, y3: int)

    Draws a triangle with corners at positions (x1,y1), (x2,y2) and (x3,y3).

  • polygon

    polygon(xs: list[int], ys: list[int])

    Draws a polygon with corners at positions (xi,yi) from xs and ys.

  • img

    img(x: int, y: int, w: int, h: int url: string)

    Draws the image loaded from the url at position (x,y) with width w and height h.

  • text

    text(x: int, y: int, t: string)

    Draws the text t at position (x,y).

• Colour Functions

  • rbg

    rgb(r: int, g: int, b: int) -> colour

    Returns the colour for the respecive red, green and blue values.

  • rbga

    rgba(r: int, g: int, b: int, a: float) -> colour

    Returns the colour for the respecive red, green and blue and alpha values. Alpha is opacity, in the range 0.0 to 1.0.

  • red

    red: colour

    The built in colour red, equivalent to rgb(240, 51, 51).

  • green

    green: colour

    The built in colour green, equivalent to rgb(98, 203, 166).

  • blue

    blue: colour

    The built in colour blue, equivalent to rgb(117, 117, 232).

  • pink

    pink: colour

    The built in colour pink, equivalent to rgb(197, 89, 146).

  • yellow

    yellow: colour

    The built in colour yellow, equivalent to rgb(221, 192, 107).

  • white

    white: colour

    The built in colour white, equivalent to rgb(255, 255, 255).

  • black

    black: colour

    The built in colour black, equivalent to rgb(0, 0, 0).

  • transparent

    transparent: colour

    The built in colour transparent, equivalent to rgba(0, 0, 0, 0.0).

• Canvas Functions

  • width

    width: int

    The width of the canvas in pixels.

  • height

    height: int

    The height of the canvas in pixels.

  • line_colour

    line_colour(c: colour)

    Sets the canvas line colour to c.

  • fill_colour

    fill_colour(c: colour)

    Sets the canvas fill colour to c.

  • line_width

    line_width(w: int)

    Sets the canvas line width to w.

  • font_size

    font_size(s: int)

    Sets the canvas font size to s.

  • translate

    translate(x: int, y: int)

    Translates the canvas by (x,y).

  • rotate

    rotate(a: int)

    Rotates the canvas by angle a in degrees.

  • scale

    scale(x: float, y: float)

    Scales the canvas size by (x,y).

  • frame_rate

    frame_rate(s: int)

    Sets the frame rate of the definable draw function.

  • stop_draw

    stop_draw(s: int)

    Stops the execution of the definable draw function.

• Definable Functions

  • draw

    def draw():

    Is called at frame_rate, intended for animations and games on the canvas.

  • left_pressed

    def left_pressed():

    Is called whenever the left arrow key is pressed.

  • right_pressed

    def right_pressed():

    Is called whenever the right arrow key is pressed.

  • up_pressed

    def up_pressed():

    Is called whenever the up arrow key is pressed.

  • down_pressed

    def down_pressed():

    Is called whenever the down arrow key is pressed.

  • space_pressed

    def space_pressed():

    Is called whenever the space key is pressed.

Can't find what you're looking for?

Check the tutorials page for more!