np.save() and np.load() for binary in NumPy - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does np.save() do in NumPy?

np.save() saves a NumPy array to a binary file on your disk. This file stores the array data efficiently so you can load it later.

beginner

How do you load a NumPy array saved with np.save()?

You use np.load() with the filename to read the binary file and get back the original NumPy array.

intermediate

Why use binary files with np.save() instead of text files?

Binary files are faster to read/write and use less space. They keep the exact data format without converting to text, which can lose precision or be slower.

beginner

What file extension does np.save() add by default?

It adds .npy to the filename automatically if you don't include it.

intermediate

Can np.load() load files saved by np.save() from different Python sessions or machines?

Yes, as long as the file is not corrupted and the NumPy versions are compatible, np.load() can load the saved binary array across sessions or machines.

What is the default file extension added by np.save()?

A .csv

B .txt

C .npy

D .bin

np.save() automatically adds the .npy extension to the saved file.

Which function do you use to read a binary file saved by np.save()?

A np.load()

B np.read()

C np.open()

D np.import()

np.load() is used to load arrays saved in binary format by np.save().

Why is saving arrays in binary format better than saving as text?

A Binary files convert data to strings

B Binary files are slower to read

C Binary files are human-readable

D Binary files save space and keep exact data

Binary files save space and keep the exact data without converting it to text, making them faster and more precise.

If you save an array with np.save('data'), what is the actual filename?

A data.npy

B data

C data.txt

D data.bin

np.save() adds .npy automatically, so the file is data.npy.

Can np.load() open files saved by np.save() on another computer?

A Only if saved as CSV

B Yes, if the file is intact and NumPy versions are compatible

C Only if the file is converted to text first

D No, only on the same computer

np.load() can load saved binary files across machines if the file is not corrupted and NumPy versions match.

Explain how to save and load a NumPy array using np.save() and np.load().

Think about saving data to disk and reading it back exactly.

Why is it better to save NumPy arrays in binary format rather than as text files?

Consider speed, size, and data accuracy.