a = b"123"
print(a)
print(str(a))
print(repr(a))
print(a[0], a[2])
print(a[-1])
print(str(a, "utf-8"))
print(str(a, "utf-8", "ignore"))
try:
    str(a, "utf-8", "ignore", "toomuch")
except TypeError:
    print("TypeError")

s = 0
for i in a:
    s += i
print(s)


print(bytes("abc", "utf-8"))
print(bytes("abc", "utf-8", "replace"))
try:
    bytes("abc")
except TypeError:
    print("TypeError")
try:
    bytes("abc", "utf-8", "replace", "toomuch")
except TypeError:
    print("TypeError")

print(bytes(3))

print(bytes([3, 2, 1]))
print(bytes(range(5)))

def gen():
    for i in range(4):
        yield i
print(bytes(gen()))