title: Got ValueErrror: too many values to unpack when trying to use train_test_split from scikit-learn
body: <p><code>**valueerrror:** too many values to unpack (expected 2)</code></p>
  <p>I'm getting this error while splitting my <code>.csv</code> mnist dataset.</p>
  <p>What am I doing wrong?</p>
  <pre><code>import tensorflow as tf
  from tensorflow import keras
  import seaborn as sns
  import matplotlib.pyplot as plt
  %matplotlib inline
  import numpy as np
  import pandas as pd
  df=pd.read_csv(&quot;/content/drive/MyDrive/digit_svm.csv&quot;)
  x = df.iloc[:,1:784].values
  y = df.iloc[:,0].values
  from sklearn.model_selection import train_test_split
  (x_train,x_test), (y_train,y_test) = train_test_split(x,y,test_size=0.2)
  </code></pre>
  <p>the error is on the last line. it shows this:</p>
  <pre><code>ValueError                                Traceback (most recent call last)
  &lt;ipython-input-54-832086f0fd65&gt; in &lt;module&gt;()
  ----&gt; 1 (x_train,x_test), (y_train,y_test) =  train_test_split(x,y,test_size=0.2)
  
  ValueError: too many values to unpack (expected 2)
  </code></pre>