Scikit-learn tutorial gives me a depreciation error, how to update?

Question

I acquired a copy of Mastering Machine Learning with scikit-learn, and I began working through it. However, it seems that a good amount of the code is now outdated.

The first code snippet in the book,

import matplotlib.pyplot as plt
X = [[6], [8], [10], [14],   [18]]
y = [[7], [9], [13], [17.5], [18]]
plt.figure()
plt.title('Pizza price plotted against diameter')
plt.xlabel('Diameter in inches')
plt.ylabel('Price in dollars')
plt.plot(X, y, 'k.')
plt.axis([0, 25, 0, 25])
plt.grid(True)
plt.show()

Ran just fine. However, when I moved on to the second one:

from sklearn.linear_model import LinearRegression
# Training data
X = [[6], [8], [10], [14],   [18]]
y = [[7], [9], [13], [17.5], [18]]
# Create and fit the model
model = LinearRegression()
model.fit(X, y)
print 'A 12" pizza should cost: $%.2f' % model.predict([12])[0]

It gave me an error:

 A 12-inch pizza should cost: $%.2f
 /home/dave/anaconda3/lib/python3.5/site-packages/sklearn/utils/validation.py:386: DeprecationWarning: Passing 1d arrays as data is deprecated in 0.17 and willraise ValueError in 0.19. Reshape your data either using X.reshape(-1, 1) if your data has a single feature or X.reshape(1, -1) if it contains a single sample.
   DeprecationWarning)
 Traceback (most recent call last):
   File "002----Chapter2-B.py", line 11, in <module>
     print ("A 12-inch pizza should cost: $%.2f") % model.predict([12])[0]
 TypeError: unsupported operand type(s) for %: 'NoneType' and 'float'

When it should have given me this:

 A 12" pizza should cost: $13.68

Is there anyway to fix this?

Surely the textbook should specify the version of scikit-learn it is written for...? — joeln, Apr 13 '16 at 00:41

score 1 · Accepted Answer · 2016-04-12T20:21:59.680

1

Try the following:

print ("A 12-inch pizza should cost: $%.2f" % model.predict(np.array([12]).reshape(1, -1)[0]))

I used reshape(1,-1) for passing 2d array to predict function.

edited Apr 12 '16 at 20:21

answered Apr 12 '16 at 20:15

That gave me an `SyntaxError: unexpected EOF while parsing` error. – Rich Apr 12 '16 at 20:20
sorry, i missed ')' at the end – Apr 12 '16 at 20:21
write 'import numpy as np' at the fisrt line of file – Apr 12 '16 at 21:22
Wait, that was wrong. It's still giving me a `DeprecationWarning` error, even though it now gives me the correct answer afterwards. – Rich Apr 12 '16 at 21:55

score 0 · Answer 2 · edited Apr 12 '18 at 14:00

0

Here's the code:

print('A ' + diameter + ' inch pizza should cost: $%.2f' % model.predict([d] [0]))

The documentation pages give more details about the predict method:

sklearn.svm.libsvm.predict()

Parameters:

X : array-like, dtype=float, size=[n_samples, n_features]

edited Apr 12 '18 at 14:00

Jules Dupont

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answered Apr 12 '18 at 13:46

user9636606

1

Scikit-learn tutorial gives me a depreciation error, how to update?

2 Answers2