iloc giving IndexError single positional indexer is out-of-bounds

Question

I was trying to encode some information to read into a Machine Learning model using the following:

import numpy as np
import pandas as pd
import matplotlib.pyplot as py

Dataset = pd.read_csv('filename.csv', sep = ',')

X = Dataset.iloc[:,:-1].values
Y = Dataset.iloc[:,18].values

from sklearn.preprocessing import LabelEncoder, OneHotEncoder
labelencoder_X = LabelEncoder()
X[:, 0] = labelencoder_X.fit_transform(X[:, 0])
onehotencoder = OneHotEncoder(categorical_features = [0])
X = onehotencoder.fit_transform(X).toarray()

But I am getting this error:

IndexError: single positional indexer is out-of-bounds

Can someone help me with this error?