Python "TypeError: unhashable type: 'slice'" for encoding categorical data

Question

I am getting

TypeError: unhashable type: 'slice'

when executing the below code for encoding categorical data in Python. Can anyone please help?

# Importing the libraries
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd

# Importing the dataset
dataset = pd.read_csv('50_Startups.csv')
y=dataset.iloc[:, 4]
X=dataset.iloc[:, 0:4]

# Encoding categorical data
from sklearn.preprocessing import LabelEncoder, OneHotEncoder
labelencoder_X = LabelEncoder()
X[:, 3] = labelencoder_X.fit_transform(X[:, 3])

What's in the csv file? In which line you got the TypeError? — am.rez, Apr 08 '17 at 04:39
Tell use about the `dataset`? I suspect its 'iloc' is expecting a string column label, not 2d array like slicing. The error implies that a `slice` (e.g 0:4) is being used in as dictionary key, or something like that. — hpaulj, Apr 08 '17 at 06:31

score 104 · Answer 1 · edited Jan 25 '19 at 05:32

X is a dataframe and can't be accessed via slice terminology like X[:, 3]. You must access via iloc or X.values. However, the way you constructed X made it a copy... so. I'd use values

# Importing the libraries
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd

# Importing the dataset
# dataset = pd.read_csv('50_Startups.csv')

dataset = pd.DataFrame(np.random.rand(10, 10))
y=dataset.iloc[:, 4]
X=dataset.iloc[:, 0:4]

# Encoding categorical data
from sklearn.preprocessing import LabelEncoder, OneHotEncoder
labelencoder_X = LabelEncoder()

#  I changed this line
X.values[:, 3] = labelencoder_X.fit_transform(X.values[:, 3])

score 8 · Answer 2 · answered Nov 26 '17 at 14:38

use Values either while creating variable X or while encoding as mentioned above

# Importing the libraries
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd

# Importing the dataset
# dataset = pd.read_csv('50_Startups.csv')

dataset = pd.DataFrame(np.random.rand(10, 10))
y=dataset.iloc[:, 4].values
X=dataset.iloc[:, 0:4].values

score 4 · Answer 3 · edited Feb 23 '18 at 18:08

4

While creating the matrix X and Y vector use values.

X=dataset.iloc[:,4].values
Y=dataset.iloc[:,0:4].values

It will definitely solve your problem.

edited Feb 23 '18 at 18:08

Stephen Kennedy

18,869
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answered Feb 23 '18 at 17:51

Gurbaksh Singh

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Hi, I'm curious about the reason of `TypeError: unhashable type: 'slice'`? – WY Hsu Aug 17 '18 at 03:27

score 1 · Answer 4 · edited Oct 23 '18 at 18:37

if you use .Values while creating the matrix X and Y vectors it will fix the problem.

y=dataset.iloc[:, 4].values

X=dataset.iloc[:, 0:4].values

when you use .Values it creates a Object representation of the created matrix will be returned with the axes removed. Check the below link for more information

https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.values.html

score 0 · Answer 5 · edited Jun 06 '18 at 08:53

0

I was getting same error (TypeError: unhashable type: 'slice') with below code:

included_cols = [2,4,10]
dataset = dataset[:,included_cols]  #Columns 2,4 and 10 are included.

Resolved with below code by putting iloc after dataset:

included_cols = [2,4,10]
dataset = dataset.iloc[:,included_cols]  #Columns 2,4 and 10 are included.

edited Jun 06 '18 at 08:53

Robert

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answered Jun 06 '18 at 08:36

Sunitha G

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score 0 · Answer 6 · answered Aug 01 '18 at 19:09

0

Try by changing X[:,3] to X.iloc[:,3] in label encoder

answered Aug 01 '18 at 19:09

Anvesh

63
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score -2 · Answer 7 · answered Nov 26 '18 at 19:13

Your x and y values are not running so first of all youre begin to write this point

 import numpy as np
 import pandas as pd
 import matplotlib as plt

 dataframe=pd.read_csv(".\datasets\Position_Salaries.csv")

 x=dataframe.iloc[:,1:2].values 
 y=dataframe.iloc[:,2].values    
 x1=dataframe.iloc[:,:-1].values

point of value have publish

Python "TypeError: unhashable type: 'slice'" for encoding categorical data

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