# Python Scikit-learn: K Nearest Neighbors - Calculate the accuracy of the model using the K Nearest Neighbor Algorithm

## Python Machine learning K Nearest Neighbors: Exercise-5 with Solution

Write a Python program using Scikit-learn to split the iris dataset into 80% train data and 20% test data. Out of total 150 records, the training set will contain 120 records and the test set contains 30 of those records. Train or fit the data into the model and calculate the accuracy of the model using the K Nearest Neighbor Algorithm.

**Sample Solution:**

**Python Code:**

```
# Import necessary modules
import pandas as pd
from sklearn.neighbors import KNeighborsClassifier
from sklearn.model_selection import train_test_split
iris = pd.read_csv("iris.csv")
#Drop id column
iris = iris.drop('Id',axis=1)
X = iris.iloc[:, :-1].values
y = iris.iloc[:, 4].values
#Split arrays or matrices into train and test subsets
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.20)
knn = KNeighborsClassifier(n_neighbors=7)
knn.fit(X_train, y_train)
# Calculate the accuracy of the model
print("Accuracy of the model:")
print(knn.score(X_test, y_test))
```

Sample Output:

Accuracy of the model: 0.9666666666666667

**Python Code Editor:**

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**Previous:** Write a Python program using Scikit-learn to convert Species columns in a numerical column of the iris dataframe. To encode this data map convert each value to a number. e.g. Iris-setosa:0, Iris-versicolor:1, and Iris-virginica:2. Now print the iris dataset into 80% train data and 20% test data. Out of total 150 records, the training set will contain 120 records and the test set contains 30 of those records. Print both datasets.

**Next:** Write a Python program using Scikit-learn to split the iris dataset into 80% train data and 20% test data. Out of total 150 records, the training set will contain 120 records and the test set contains 30 of those records. Train or fit the data into the model and using the K Nearest Neighbor Algorithm calculate the performance for different values of k.

**What is the difficulty level of this exercise?**

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