#!/usr/bin/env python
# coding: utf-8

# In[1]:


import numpy as np
from scipy.spatial.distance import cdist
from sklearn.datasets import load_iris
from sklearn.preprocessing import StandardScaler
from sklearn.neighbors import NearestCentroid as skNearestCentroid


# In[2]:


class NearestCentroid():
    def fit(self, X, y):
        self.classes_ = np.unique(y)
        self.centroids_ = np.zeros((len(self.classes_), X.shape[1]))
        for i, c in enumerate(self.classes_):
            self.centroids_[i] = np.mean(X[y == c], axis=0)
        return self

    def predict(self, X):
        return self.classes_[np.argmin(cdist(X, self.centroids_), axis=1)]


# In[3]:


X, y = load_iris(return_X_y=True)
X = StandardScaler().fit_transform(X)
clf1 = NearestCentroid().fit(X, y)
clf2 = skNearestCentroid().fit(X, y)
assert np.allclose(clf1.centroids_, clf2.centroids_)
pred1 = clf1.predict(X)
pred2 = clf2.predict(X)
assert np.array_equal(pred1, pred2)