为何Python仅输出含‘...’的6个数字而非10000个？NumPy数组疑问

Hey there! Great question—this is a super common behavior with NumPy that trips up a lot of folks when they first start working with large arrays. Let’s break it down:

1. Why you don’t see all 10000 numbers #

NumPy has a built-in default setting to truncate long array outputs when you print them out. The reason for this is simple: dumping 10000 numbers into your terminal or notebook would create a huge wall of text, making it hard to read and cluttering up your workspace. It’s NumPy’s way of keeping your output clean and focused on the parts that matter at a glance.

2. What the '...' represents #

That little ... is a placeholder for the omitted elements. When you see output like [4528679 4547733 119675 ... 2215797 1247 1703543], it means:

• The first 3 elements of your array are 4528679, 4547733, 119675
• The last 3 elements are 2215797, 1247, 1703543
• Everything in between (the other 9994 elements!) is hidden behind the ...

How to show the full array if you need to #

If you do want to see all 10000 elements, you can override NumPy’s default print settings with np.set_printoptions(). Just run this line before printing your array:

import numpy as np
np.set_printoptions(threshold=np.inf)

After that, printing y will spit out every single element in your array. Just be warned—this might make your output pretty long!

内容的提问来源于stack exchange，提问作者Andrew DeNike