Why do I get Value error when building Linear Regression model?

Question

I'm trying to build a Linear Regression model for a dataset. After splitting the data into train and test, I get the below error:

ValueError: could not convert string to float: '?' Does that mean, there is null value or a float value in the dataset?

As I'm new to Python, I don't understand how to rectify this. Could anyone help me on this?

import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn import linear_model
df = pd.read_csv('https://archive.ics.uci.edu/ml/machine-learning-databases/breast-cancer-wisconsin/breast-cancer-wisconsin.data', names = ['ID Number', 'Clump Thickness', 'Uniformity of Cell Size', 'Uniformity of Cell Shape', 'Marginal Adhesion', 'Single Epithelial Cell Size', 'Bare Nuclei', 'Bland Chromatin', 'Normal Nucleoli', 'Mitoses', 'Class'])
X = df.iloc[:, 0:9].values
y = df.iloc[:, 10].values
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 0.4, random_state = 4)
print(X_train.shape)
print(y_train.shape)
print(X_test.shape)
print(y_test.shape)
lr = linear_model.LinearRegression()
lr.fit(X_train, y_train)

Looks like one of the column is of type object. Type X.dtype and check datatype of each column in your data. — Sociopath
Yes, one column is of datatype 'Object'. I got the output after deleting that column. Thanks — Sruthi

Abhishri Abhishri · Accepted Answer · 2019-07-18T05:58:47

The breast-cancer-wisconsin.data Dataset that you are using has some rows with '?' as value in 7th column. So when you create X and y don't consider the rows with '?' as value.

I hope this helps.

Why do I get Value error when building Linear Regression model?

1 Answers