ImportError: cannot import name 'train_test_split' from sklearn.model_selection

ImportError: cannot import name ‘train_test_split’

$ python -c "from sklearn.model_selection import train_test_split"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: cannot import name 'train_test_split' from 'sklearn.model_selection' (unknown location)

Why this happens

• scikit-learn is not installed or the environment is wrong.
• You shadowed the package with a local file or folder named sklearn/.
• Very old scikit-learn version missing model_selection module.

Fix

• Install/upgrade scikit-learn and ensure you’re in the right environment.
• Remove/rename local sklearn.py or sklearn/ directories.
• Use the correct import path.

Wrong code

# local file named sklearn.py in project directory
from sklearn.model_selection import train_test_split
X = [1,2,3]
y = [0,1,0]
X_train, X_test, y_train, y_test = train_test_split(X, y)

Fixed code

# Ensure scikit-learn is installed and not shadowed
from sklearn.model_selection import train_test_split
X = [[1],[2],[3]]
y = [0,1,0]
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42)
print(len(X_train), len(X_test))