Syntax

# Single-line comment
x = 1  # Trailing comment

"""
Triple-quoted strings used as
module-level documentation are
parsed but discarded.
"""

counter = 0
café = "open"
π = 3.14159

# Multiple targets
a = b = c = 0
print(a, b, c)

a, b = 1, 2
print(a, b)

# Star pattern
first, *middle, last = [1, 2, 3, 4, 5]
print(first, middle, last)

data = [1, 2, 3]
if (n := len(data)) > 0:
    print(n)

# Integers — arbitrary precision
print(2 ** 100)
print(0xDEAD_BEEF)
print(0o777)
print(0b1010_1010)
print(1_000_000)

# Floats — IEEE-754
print(3.14)
print(1e-5)
print(.5)

# Mixed arithmetic coerces to float
print(2 + 3.0)

print('single')
print("double")
print("""triple
quoted""")
print(r'raw\n')           # backslash not escaped
print('hello' ' world')   # implicit concatenation

print('\n line break')
print('\t tab')
print('\x41 hex')
print('\u00e9 unicode')

name = "world"
n = 42
print(f"hello {name}")
print(f"answer is {n + 1}")
print(f"{n:04d}")     # format spec
print(f"{{literal braces}}")

print(True, False, None)
print(bool(0), bool(1), bool(""), bool("x"))
print(not True)

print(7 + 3, 7 - 3, 7 * 3, 7 / 3)
print(7 // 3, 7 % 3, 2 ** 10)
print(-5, +5)

print(1 < 2 < 3)        # chained
print(0 < 5 < 10)
print(1 == 1 == 1)

print(True and "second")
print(0 or "fallback")
print(None or 0 or [] or "default")

print(5 & 3, 5 | 3, 5 ^ 3, ~5)
print(1 << 4, 32 >> 2)

print(2 in [1, 2, 3])
print('a' in {'a': 1})
print(None is None)
print(1 is not 2)

x = 10
x += 5
x *= 2
print(x)

x = 5
print("big" if x > 3 else "small")

xs = [1, 2, 3]
print(xs[0], xs[-1])
print(xs[1:3])
print(xs + [4, 5])
print(xs * 2)

t = (1, 2, 3)
print(t[1])
print((1,))      # singleton needs the comma
print(())        # empty tuple

d = {"a": 1, "b": 2}
print(d["a"])
d["c"] = 3
print(d)
print(list(d.keys()))

s = {1, 2, 2, 3}
print(s)
print(2 in s)
print(set())     # empty set literal needs the function

a = [1, 2, 3, 4, 5]
print(a[1:4])      # [start:stop]
print(a[:2])
print(a[3:])
print(a[::2])      # every 2nd
print(a[::-1])     # reversed

print([x * x for x in range(5)])
print([x for x in range(10) if x % 2 == 0])
print([(i, j) for i in range(2) for j in range(2)])
print({x: x * x for x in range(4)})
print({x % 3 for x in range(10)})

print(sum(x * x for x in range(5)))
print(max(x for x in [3, 1, 4, 1, 5]))

counter: int = 0
name: str = "edge"

def add(a: int, b: int) -> int:
    return a + b

print(add(3, 4))