title: How to solve " multiclass format is not supported" error in python?
body: <p>It is my code:</p>
  
  <pre><code>import numpy as np
  import pandas as pd
  import seaborn as sns 
  import matplotlib.pyplot as plt
  import os
  from sklearn import preprocessing
  
  df_train = pd.read_csv('Iris_train.csv')
  df_test = pd.read_csv('Iris_test.csv')
  
  X_train = df_train.drop(['TYPE'],axis=1).values
  y_train = df_train_fixed[['TYPE']].values
  X_test = df_test.values
  from sklearn import preprocessing
  std_scaler = preprocessing.StandardScaler()
  std_scaler.fit(X_train)
  X_train_std_sk = std_scaler.transform(X_train)
  X_test_std_sk = std_scaler.transform(X_test)
  
  from sklearn.linear_model import LogisticRegression
  logreg = LogisticRegression(penalty='l2', 
                              solver='saga', 
                              multi_class='ovr')
  logreg.fit(X_train_std_sk,y_train.ravel() )
  y_pred = logreg.predict(X_test_std_sk)
  y_pred
  
  y_real = pd.read_csv('Iris_test_labels.csv').values
  from sklearn.metrics import confusion_matrix
  confusion_matrix(y_real,y_pred)
  from sklearn.metrics import accuracy_score
  accuracy_score(y_real,y_pred)
  y_prob=logreg.predict_proba(X_test_std_sk)
  y_score=logreg.predict_proba(X_test_std_sk)[:,1]
  from sklearn.metrics import roc_curve
  y_real
  fpr,tpr,thresholds=roc_curve(y_real, y_score)
  
  </code></pre>
  
  <p>after this code then error come. I don't know why. The detailed error is </p>
  
  <pre><code>---------------------------------------------------------------------------
  ValueError                                Traceback (most recent call last)
  &lt;ipython-input-178-2d9f99ac1496&gt; in &lt;module&gt;
  ----&gt; 1 fpr,tpr,thresholds=roc_curve(y_real, y_score)
  
  ~\Anaconda3\lib\site-packages\sklearn\metrics\_ranking.py in roc_curve(y_true, y_score, pos_label, sample_weight, drop_intermediate)
      769     """
      770     fps, tps, thresholds = _binary_clf_curve(
  --&gt; 771         y_true, y_score, pos_label=pos_label, sample_weight=sample_weight)
      772 
      773     # Attempt to drop thresholds corresponding to points in between and
  
  ~\Anaconda3\lib\site-packages\sklearn\metrics\_ranking.py in _binary_clf_curve(y_true, y_score, pos_label, sample_weight)
      534     if not (y_type == "binary" or
      535             (y_type == "multiclass" and pos_label is not None)):
  --&gt; 536         raise ValueError("{0} format is not supported".format(y_type))
      537 
      538     check_consistent_length(y_true, y_score, sample_weight)
  
  ValueError: multiclass format is not supported
  
  </code></pre>
  
  <p>That is I don't know how to solve this problem. </p>