x = None
arr = [1, 2, 3]
try:
while True:
x = next(iter(arr))
except StopIteration:
pass
print(x)
Задачи по питону и машинному обучению: алгоритмы, функции, классы, регулярные выражения, итераторы, генераторы, ООП, исключения, numpy, pandas, matplotlib, scikit-learn, TensorFlow и др. #Python #ml
x = None
arr = [1, 2, 3]
try:
while True:
x = next(iter(arr))
except StopIteration:
pass
print(x)x = None
arr = [1, 2, 3]
arr = iter(arr)
try:
while True:
x = next(arr)
except StopIteration:
pass
print(x)import numpy as np
# Данные: каждая строка соответствует корзине для покупок конкретного покупателя
# строка = [товар 1, товар 2, товар 3]
# значение 1 означает, что товар был куплен
basket = np.array([[1, 1, 0],
[0, 0, 1],
[1, 0, 0],
[1, 1, 1],
[1, 1, 0]])
copurchases = [(i, j, np.sum(basket[:, i] + basket[:, j] == 2)) for i in range(3) for j in range(i+1, 3)]
result = max(copurchases, key=lambda x:x[2])
# Первые два значения кортежа result - индексы товаров-столбцов. Третье - число раз, когда они покупались вместе.
print(result)from sklearn.neighbors import KNeighborsRegressor import numpy as np X = np.array([[35, 30000], [45, 45000], [40, 50000], [35, 35000], [25, 32500], [40, 40000]]) KNN = KNeighborsRegressor(n_neighbors=3).fit(X[:,0].reshape(-1,1), X[:,1]) res = KNN.predict([[30]]) print(int(res[0]))
import numpy as np
a = np.array([[0, 1, 2, 3],
[4, 5, 6, 7],
[8, 9, 10, 11],
[12, 13, 14, 15]])
print(a[-1, :-1][::-2][-2])import numpy as np
a = np.array([[0, 1, 2, 3],
[4, 5, 6, 7],
[8, 9, 10, 11],
[12, 13, 14, 15]])
print(a[1, :][-1] + a[:, 1][-1])import numpy as np
a = np.array([[0, 1, 2, 3],
[4, 5, 6, 7],
[8, 9, 10, 11],
[12, 13, 14, 15]])
print(a[:, 2])import numpy as np alice = [100, 200] #зарплата Алисы за первый и второй год bob = [300, 400] #зарплата Боба за первый и второй год salaries = np.array([alice, bob]) taxation = np.array([[0.2, 0.3], [0.1, 0.5]]) #ставки налогов max_income = np.max(salaries - salaries * taxation) print(max_income)
import numpy as np basket = np.array([[1, 1, 1, 1], [1, 1, 1, 0]]) co_purchases = np.sum(np.all(basket[:,2:], axis = 1)) / basket.shape[0] print(co_purchases)
import numpy as np basket = np.array([[1, 1, 1, 1], [1, 1, 1, 0]]) co_purchases = np.sum(np.all(basket[:,2:], axis = 1)) / basket.shape[0] print(co_purchases)
import numpy as np basket = np.array([[1, 1, 1, 1], [1, 1, 1, 0]]) x = np.all(basket[:,2:], axis = 1) print(*x)
import numpy as np
a = np.array([1, 2, 3])
np.save('mydata', a)import numpy as np a = np.array([[1, 2, 0, 3], [4, 0, 1, 1]]) print(np.any(a), np.all(a))
import numpy as np a = np.array([1, 0, 0]) b = np.array([0, 1, 0]) c = np.cross(a, b) print(c)
(lambda x: x**3 if [] or None or 1 and [True] else lambda x: x)(2)
x = [[0]] x = x + x * 2 x[0].append(1) x[1].append(2) print(x)
f = lambda x: type(x) g = f(f(f(f(f(f))))) print(g)