D:\>pip install freegames -i https://pypi.tuna.tsinghua.edu.cn/simple/
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple/
Collecting freegames
  Downloading https://pypi.tuna.tsinghua.edu.cn/packages/62/f5/643ebe95085f1fea2
d8e4597259d8c56a920df1ed10dcfb65d7b80caff4f/freegames-2.4.0-py3-none-any.whl (10
8 kB)
     ------------------------------------ 109.0/109.0 kB 528.1 kB/s eta 0:00:00
Installing collected packages: freegames
Successfully installed freegames-2.4.0

    DESCRIPTION
        Free Python Games is an Apache2 licensed collection of free Python games
        intended for education and fun. The games are written in simple Python code and
        designed for experimentation and changes. Simplified versions of several
        classic arcade games are included.
        Python is one of the top-five most popular programming languages in the world
        and available for free from www.python.org. Python includes an extensive
        Standard Library distributed with your installation. The Standard Library has a
        module called Turtle which is a popular way to introduce programming to
        kids. Turtle was part of the original Logo programming language developed by
        Wally Feurzig and Seymour Papert in 1966. All of the games in Free Python Games
        are implemented using Python and its Turtle module.
        Starting in 2012, Free Python Games began as an after school program to teach
        programming to inner-city youth. The goal was to have fun as much as it was to
        learn. Since then the games have been improved and used in a variety of
        settings ranging from classrooms to summer day-camps.
        The games run anywhere Python can be installed which includes desktop computers
        running Windows, Mac OS, or Linux and older or low-power hardware such as the
        Raspberry Pi. Kids across the United States in grades 6th-12th have enjoyed
        learning about topics such as encryption and projectile motion through games.
        Each game is entirely independent from the others and includes comments along
        with a list of exercises to work through with students. Creativity and
        flexibility is important. There is no right or wrong way to implement a new
        feature or behavior! You never know which games students will engage with best.
        Free Python Games supports a command-line interface (CLI). Help for the CLI is
        available using::
          $ python3 -m freegames --help
        The CLI supports three commands: list, copy, and show. For a list of all games
        run::
          $ python3 -m freegames list
        Any of the listed games may be played by executing the Python module from the
        command-line. To reference the Python module, combine "freegames" with the name
        of the game. For example, to play the "snake" game run::
          $ python3 -m freegames.snake
        Games can be modified by copying their source code. The copy command will
        create a Python file in your local directory which you can edit. For example,
        to copy and play the "snake" game run::
          $ python3 -m freegames copy snake
          $ python3 snake.py
        Python includes a built-in text editor named IDLE which can also execute Python
        code. To launch the editor and make changes to the "snake" game run::
          $ python3 -m idlelib.idle snake.py

D:\>python -m freegames list
ant
bagels
bounce
cannon
connect
crypto
fidget
flappy
guess
life
madlibs
maze
memory
minesweeper
pacman
paint
pong
simonsays
snake
tictactoe
tiles
tron

"""Maze, move from one side to another.
Excercises
1. Keep score by counting taps.
2. Make the maze harder.
3. Generate the same maze twice.
"""
from random import random
from turtle import *
from freegames import line
def draw():
    """Draw maze."""
    color('black')
    width(5)
    for x in range(-200, 200, 40):
        for y in range(-200, 200, 40):
            if random() > 0.5:
                line(x, y, x + 40, y + 40)
            else:
                line(x, y + 40, x + 40, y)
    update()
def tap(x, y):
    """Draw line and dot for screen tap."""
    if abs(x) > 198 or abs(y) > 198:
        up()
    else:
        down()
    width(2)
    color('red')
    goto(x, y)
    dot(4)
setup(420, 420, 370, 0)
hideturtle()
tracer(False)
draw()
onscreenclick(tap)
done()

"""Snake, classic arcade game.
Exercises
1. How do you make the snake faster or slower?
2. How can you make the snake go around the edges?
3. How would you move the food?
4. Change the snake to respond to mouse clicks.
"""
from random import randrange
from turtle import *
from freegames import square, vector
food = vector(0, 0)
snake = [vector(10, 0)]
aim = vector(0, -10)
def change(x, y):
    """Change snake direction."""
    aim.x = x
    aim.y = y
def inside(head):
    """Return True if head inside boundaries."""
    return -200 < head.x < 190 and -200 < head.y < 190
def move():
    """Move snake forward one segment."""
    head = snake[-1].copy()
    head.move(aim)
    if not inside(head) or head in snake:
        square(head.x, head.y, 9, 'red')
        update()
        return
    snake.append(head)
    if head == food:
        print('Snake:', len(snake))
        food.x = randrange(-15, 15) * 10
        food.y = randrange(-15, 15) * 10
    else:
        snake.pop(0)
    clear()
    for body in snake:
        square(body.x, body.y, 9, 'black')
    square(food.x, food.y, 9, 'green')
    update()
    ontimer(move, 100)
setup(420, 420, 370, 0)
hideturtle()
tracer(False)
listen()
onkey(lambda: change(10, 0), 'Right')
onkey(lambda: change(-10, 0), 'Left')
onkey(lambda: change(0, 10), 'Up')
onkey(lambda: change(0, -10), 'Down')
move()
done()

CLASSES
    collections.abc.Sequence(collections.abc.Reversible, collections.abc.Collection)
        freegames.utils.vector
    class vector(collections.abc.Sequence)
     |  vector(x, y)
     |  
     |  Two-dimensional vector.
     |  
     |  Vectors can be modified in-place.
     |  
     |  >>> v = vector(0, 1)
     |  >>> v.move(1)
     |  >>> v
     |  vector(1, 2)
     |  >>> v.rotate(90)
     |  >>> v
     |  vector(-2.0, 1.0)
     |  
     |  Method resolution order:
     |      vector
     |      collections.abc.Sequence
     |      collections.abc.Reversible
     |      collections.abc.Collection
     |      collections.abc.Sized
     |      collections.abc.Iterable
     |      collections.abc.Container
     |      builtins.object
     |  
     |  Methods defined here:
     |  
     |  __abs__(self)
     |      v.__abs__() -> abs(v)
     |      
     |      >>> v = vector(3, 4)
     |      >>> abs(v)
     |      5.0
     |  
     |  __add__(self, other)
     |      v.__add__(w) -> v + w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v + w
     |      vector(4, 6)
     |      >>> v + 1
     |      vector(2, 3)
     |      >>> 2.0 + v
     |      vector(3.0, 4.0)
     |  
     |  __eq__(self, other)
     |      v.__eq__(w) -> v == w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(1, 2)
     |      >>> v == w
     |      True
     |  
     |  __getitem__(self, index)
     |      v.__getitem__(v, i) -> v[i]
     |      
     |      >>> v = vector(3, 4)
     |      >>> v[0]
     |      3
     |      >>> v[1]
     |      4
     |      >>> v[2]
     |      Traceback (most recent call last):
     |          ...
     |      IndexError
     |  
     |  __hash__(self)
     |      v.__hash__() -> hash(v)
     |      
     |      >>> v = vector(1, 2)
     |      >>> h = hash(v)
     |      >>> v.x = 2
     |      Traceback (most recent call last):
     |          ...
     |      ValueError: cannot set x after hashing
     |  
     |  __iadd__(self, other)
     |      v.__iadd__(w) -> v += w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v += w
     |      >>> v
     |      vector(4, 6)
     |      >>> v += 1
     |      >>> v
     |      vector(5, 7)
     |  
     |  __imul__(self, other)
     |      v.__imul__(w) -> v *= w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v *= w
     |      >>> v
     |      vector(3, 8)
     |      >>> v *= 2
     |      >>> v
     |      vector(6, 16)
     |  
     |  __init__(self, x, y)
     |      Initialize vector with coordinates: x, y.
     |      
     |      >>> v = vector(1, 2)
     |      >>> v.x
     |      1
     |      >>> v.y
     |      2
     |  
     |  __isub__(self, other)
     |      v.__isub__(w) -> v -= w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v -= w
     |      >>> v
     |      vector(-2, -2)
     |      >>> v -= 1
     |      >>> v
     |      vector(-3, -3)
     |  
     |  __itruediv__(self, other)
     |      v.__itruediv__(w) -> v /= w
     |      
     |      >>> v = vector(2, 4)
     |      >>> w = vector(4, 8)
     |      >>> v /= w
     |      >>> v
     |      vector(0.5, 0.5)
     |      >>> v /= 2
     |      >>> v
     |      vector(0.25, 0.25)
     |  
     |  __len__(self)
     |      v.__len__() -> len(v)
     |      
     |      >>> v = vector(1, 2)
     |      >>> len(v)
     |      2
     |  
     |  __mul__(self, other)
     |      v.__mul__(w) -> v * w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v * w
     |      vector(3, 8)
     |      >>> v * 2
     |      vector(2, 4)
     |      >>> 3.0 * v
     |      vector(3.0, 6.0)
     |  
     |  __ne__(self, other)
     |      v.__ne__(w) -> v != w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v != w
     |      True
     |  
     |  __neg__(self)
     |      v.__neg__() -> -v
     |      
     |      >>> v = vector(1, 2)
     |      >>> -v
     |      vector(-1, -2)
     |  
     |  __radd__ = __add__(self, other)
     |  
     |  __repr__(self)
     |      v.__repr__() -> repr(v)
     |      
     |      >>> v = vector(1, 2)
     |      >>> repr(v)
     |      'vector(1, 2)'
     |  
     |  __rmul__ = __mul__(self, other)
     |  
     |  __sub__(self, other)
     |      v.__sub__(w) -> v - w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v - w
     |      vector(-2, -2)
     |      >>> v - 1
     |      vector(0, 1)
     |  
     |  __truediv__(self, other)
     |      v.__truediv__(w) -> v / w
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> w / v
     |      vector(3.0, 2.0)
     |      >>> v / 2
     |      vector(0.5, 1.0)
     |  
     |  copy(self)
     |      Return copy of vector.
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = v.copy()
     |      >>> v is w
     |      False
     |  
     |  move(self, other)
     |      Move vector by other (in-place).
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v.move(w)
     |      >>> v
     |      vector(4, 6)
     |      >>> v.move(3)
     |      >>> v
     |      vector(7, 9)
     |  
     |  rotate(self, angle)
     |      Rotate vector counter-clockwise by angle (in-place).
     |      
     |      >>> v = vector(1, 2)
     |      >>> v.rotate(90)
     |      >>> v == vector(-2, 1)
     |      True
     |  
     |  scale(self, other)
     |      Scale vector by other (in-place).
     |      
     |      >>> v = vector(1, 2)
     |      >>> w = vector(3, 4)
     |      >>> v.scale(w)
     |      >>> v
     |      vector(3, 8)
     |      >>> v.scale(0.5)
     |      >>> v
     |      vector(1.5, 4.0)
     |  
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |  
     |  x
     |      X-axis component of vector.
     |      
     |      >>> v = vector(1, 2)
     |      >>> v.x
     |      1
     |      >>> v.x = 3
     |      >>> v.x
     |      3
     |  
     |  y
     |      Y-axis component of vector.
     |      
     |      >>> v = vector(1, 2)
     |      >>> v.y
     |      2
     |      >>> v.y = 5
     |      >>> v.y
     |      5
     |  
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |  
     |  PRECISION = 6
     |  
     |  __abstractmethods__ = frozenset()
     |  
     |  ----------------------------------------------------------------------
     |  Methods inherited from collections.abc.Sequence:
     |  
     |  __contains__(self, value)
     |  
     |  __iter__(self)
     |  
     |  __reversed__(self)
     |  
     |  count(self, value)
     |      S.count(value) -> integer -- return number of occurrences of value
     |  
     |  index(self, value, start=0, stop=None)
     |      S.index(value, [start, [stop]]) -> integer -- return first index of value.
     |      Raises ValueError if the value is not present.
     |      
     |      Supporting start and stop arguments is optional, but
     |      recommended.
     |  
     |  ----------------------------------------------------------------------
     |  Class methods inherited from collections.abc.Reversible:
     |  
     |  __subclasshook__(C) from abc.ABCMeta
     |      Abstract classes can override this to customize issubclass().
     |      
     |      This is invoked early on by abc.ABCMeta.__subclasscheck__().
     |      It should return True, False or NotImplemented.  If it returns
     |      NotImplemented, the normal algorithm is used.  Otherwise, it
     |      overrides the normal algorithm (and the outcome is cached).
FUNCTIONS
    floor(value, size, offset=200)
        Floor of `value` given `size` and `offset`.
        The floor function is best understood with a diagram of the number line::
             -200  -100    0    100   200
            <--|--x--|-----|--y--|--z--|-->
        The number line shown has offset 200 denoted by the left-hand tick mark at
        -200 and size 100 denoted by the tick marks at -100, 0, 100, and 200. The
        floor of a value is the left-hand tick mark of the range where it lies. So
        for the points show above: ``floor(x)`` is -200, ``floor(y)`` is 0, and
        ``floor(z)`` is 100.
        >>> floor(10, 100)
        0.0
        >>> floor(120, 100)
        100.0
        >>> floor(-10, 100)
        -100.0
        >>> floor(-150, 100)
        -200.0
        >>> floor(50, 167)
        -33.0
    line(a, b, x, y)
        Draw line from `(a, b)` to `(x, y)`.
    path(filename)
        Return full path to `filename` in freegames module.
    square(x, y, size, name)
        Draw square at `(x, y)` with side length `size` and fill color `name`.
        The square is oriented so the bottom left corner is at (x, y).