Installing and importing NumPy - Practice Exercises

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of importing NumPy and checking its version?

Consider the following code that imports NumPy and prints its version.
What will be the output?

NumPy

import numpy as np
print(np.__version__)

A "1.24.2"

B SyntaxError

C ModuleNotFoundError

D "numpy"

💡 Hint

NumPy stores its version in the __version__ attribute as a string.

When you import NumPy as np, np.__version__ returns the version string installed in your environment, such as "1.24.2". It does not raise an error if NumPy is installed.

❓ Predict Output

intermediate

What error occurs if NumPy is not installed and you try to import it?

What error will this code produce if NumPy is not installed in your Python environment?

import numpy

NumPy

import numpy

A ImportError

B NameError

C ModuleNotFoundError

D SyntaxError

💡 Hint

Python raises a specific error when a module cannot be found.

If NumPy is not installed, Python raises ModuleNotFoundError when you try to import it. ImportError is a more general error but ModuleNotFoundError is the specific subclass.

🚀 Application

advanced

Which command correctly installs NumPy using pip?

You want to install NumPy in your Python environment using pip. Which command will do this correctly?

A pip install numpy

B install numpy

C pip numpy install

D python numpy install

💡 Hint

The pip command to install a package is 'pip install package_name'.

The correct pip command to install NumPy is 'pip install numpy'. Other options are invalid commands.

🔧 Debug

advanced

Why does this import statement cause an error?

Look at this code:

import numpy as npy
print(np.__version__)

Why does it cause an error?

NumPy

import numpy as npy
print(np.__version__)

A AttributeError because __version__ does not exist

B ModuleNotFoundError because numpy is not installed

C SyntaxError due to wrong import syntax

D NameError because 'np' is not defined

💡 Hint

Check the alias used in the import and the variable used in print.

The code imports numpy as 'npy' but tries to print 'np.__version__'. Since 'np' is not defined, it raises a NameError.

🧠 Conceptual

expert

What is the main reason to use 'import numpy as np' instead of 'import numpy'?

Why do most Python users write 'import numpy as np' instead of just 'import numpy'?

A To install NumPy automatically when importing

B To shorten the name for easier and faster typing in code

C To avoid errors when NumPy is not installed

D To change the version of NumPy used

💡 Hint

Think about how programmers write code efficiently.

Using 'import numpy as np' creates a short alias 'np' so you can write 'np.array()' instead of 'numpy.array()', making code shorter and easier to read.