Footgun simulator

xs = [10, 20, 30]
print(xs[-1])

grid = [[]] * 3
grid[0].append("x")
print(grid)

def collect(item, into=[]):
    into.append(item)
    return into
print(collect(1))
print(collect(2))

fns = [lambda: i for i in range(3)]
print([f() for f in fns])

print("a-b-c".replace("-", "+"))

xs = [3, 1, 2]
print(xs.sort())

for value in ([], {}, "", 0, 0.0, None, [0]):
    print(repr(value), bool(value))

print(7 / 2)
print(7 // 2)
print(-7 // 2)

print(1 < 2 < 3)
print(3 > 2 > 1)
print((1 < 2) < 3)

a, b = 256, 256
c, d = 257, 257
print(a is b, a == b)
print(c is d, c == d)

print(0.1 + 0.2)
print(0.1 + 0.2 == 0.3)

print(type((1)).__name__)
print(type((1,)).__name__)
print(len((1,)))

d = {"b": 1, "a": 2, "10": 3, "2": 4}
print(list(d))

original = [[1, 2], [3, 4]]
copy = original.copy()
copy[0].append(99)
print(original)

s = "abc"
try:
    s[0] = "z"
except TypeError as e:
    print("TypeError:", e)
print(s)

class Bag:
    items = []
a, b = Bag(), Bag()
a.items.append("x")
print(b.items)

class A:
    def __init__(self):
        self.__secret = 1
a = A()
print([n for n in vars(a)])
print(a._A__secret)

try:
    raise ValueError("boom")
except ValueError as err:
    print(err)
print("err" in dir())

squares = (x * x for x in range(3))
print(list(squares))
print(list(squares))

a = "hello world"
b = "hello world"
c = "".join(["hello", " ", "world"])
print(a is b, a == b)
print(a is c, a == c)