freiz

import numpy as np


class KMeans(object):
    def __init__(self, X, k, max_iter=100):
        assert X.shape[0] >= k, f"X must contain at least {k} samples"
        self.X = X.astype(np.float64)  # Convert X to float64
        self.k = k
        self.max_iter = max_iter

freiz

import numpy as np
from numpy.typing import NDArray


class LinearRegression(object):
    """Linear Regression model
    TODO:
        - docstring
        - input validation
        - data reformat/reshape

freiz

# A recursive function is tail recursive when a recursive call is the last thing executed by the function.

# This is not a tail recursion version
def fact(n):
    if n == 1:
        return 1
    return n * fact(n - 1)


# This is a tail recursion version

freiz

# you need to first install requests, in command window, install vai pip 'pip install requests'

import requests

def DownloadFile(url, filename=None):
  if filename is None:
    local_filename = url.split('/')[-1]
  else:
    local_filename = filename
  r = requests.get(url)

freiz

public class Singleton {
    private Singleton() {}

    /**
     * 辅助内部类
     *
     * 由于类的加载是线程安全的，这里不需要显式的锁
     */
    private static class SingletonHolder {
        private static final Singleton INSTANCE = new Singleton();