Задачи по Python и машинному обучению

import numpy as np
a = np.array((100, 101, 102, 103))
b = np.zeros_like(a)
print(np.sum(b))

import numpy as np
a = np.array((100, 101, 102, 103))
b = np.ones_like(a)
print(np.sum(b))

import numpy as np
b = np.array([[1., 2.], [3., 4.]])
b[0, 0] = 0
b[1, 1] = 0
a = np.sum(b)
print(a)

it = (lambda: i for i in [1, 2])
vals = [f() for f in [*it]]
print(sum(vals))

it = (lambda: i for i in [1, 2])
vals = [f() for f in it]
print(sum(vals))

a, *b = (1, 2, 3)
x = hasattr(a, '__iter__')
y = hasattr(b, '__iter__')
print(x, y)

import struct
s = struct.pack('fhb', 1, 1, 1)
print(len(s))

import pickle
s = pickle.dumps({"x": 1})
a = pickle.loads(s[1:])["x"]
print(a)

def dec(f):
  # Ваш код...
  def wrapper(*args, **kwargs):
    return f(*args, **kwargs)
  return wrapper

@dec
def add(a, b):
  return a + b

print(add.__name__)

from decimal import Decimal, ROUND_UP, ROUND_DOWN
a = Decimal(1)
b = Decimal(7)
c = a / b
x1 = c.quantize(Decimal('0.1'), rounding=ROUND_DOWN)
x2 = c.quantize(Decimal('0.1'), rounding=ROUND_UP)
print(x2 - x1)

class A:
    def __call__(self):
        return self
a = A()
print(a is a(), a() == a()())

def f(f): f(f)
res = f(f)
print(res)

def f(x):
    return x**3 + 6*x**2 + 12*x + 75
l = [f(i) for i in range(1, 2021, 3)]
s1 = sum([x // 2 for x in l])
s2 = sum([x >> 1 for x in l])
print(s1 - s2)

class Number(int, float): pass
x1 = Number(1)
x2 = Number(1.0)
print(x1 == x2)

s = set(dir('a')) - set(dir(b'a'))
x = 'encode' in s
y = 'decode' in s
print(x, y)

from functools import reduce
vals = (chr(x) for x in range(ord('a'), ord('d')))
print(reduce(lambda acc, x: x + acc[::-1] + x, vals, ''))

type(None) == NoneType

class MyBool(bool): pass
b = MyBool(True)
print(b == True, b is True)

try:
    raise IOError()
except OSError as err:
    print(isinstance(err, OSError), isinstance(err, IOError))

def a(z):
    x = 0
    try:
        x += 1
        100/z
        x += 1
    except ZeroDivisionError:
        try:
            x += 1
        finally:
            x += 1
            return x
    finally:
        x += 1
    return -1

print(a(0))

S = 'hello'
C = bytearray(S, encoding="ascii")

from collections import namedtuple  
rec = namedtuple('rec', ['x', 'y', 'z']) 
comp = rec(1, 2, [4, 5])

s = bytearray("hello", encoding="ascii")

import numpy as np
m = np.arange(4).reshape(2, 2)
d = np.fliplr(m).diagonal()
print(sum(d), np.trace(m))

a = [1]
a.insert(0, a)
a[0][0][-2][-2].append([2])
a[0][0][-1].append(3)
a[0][0][0][0][-1][0] *= -1
s = a[0][1] + a[0][0][2][-1] + a[0][0][2][-2]
print(s)