To convert a Python list to a NumPy array, use either of the following two methods:

1. The np.array() function that takes an iterable and returns a NumPy array creating a new data structure in memory.
2. The np.asarray() function that takes an iterable as argument and converts it to the array. The difference to np.array() is that np.asarray() doesn’t create a new copy in memory if you pass a NumPy array. All changes made on the original array are reflected on the NumPy array.

Exercise: Create array b from array a using both methods. Then change a value in array a. What happens at array b?

NumPy vs Python Lists

The Python built-in list data type is powerful. However, the NumPy array has many advantages over Python lists. What are they?

To read more about the advantages of a NumPy array over a Python list, read my detailed blog tutorial.

How to Convert a 1D Python List to a NumPy Array?

Problem: Given a one-dimensional Python list. How to convert it to a NumPy array?

Example: You have the following 1D Python list of integers.

lst = [0, 1, 100, 42, 13, 7]

You want to convert it into a NumPy array.

array([ 0, 1, 100, 42, 13, 7])

Method 1: np.array(…)

The simplest way to convert a Python list to a NumPy array is to use the np.array() function that takes an iterable and returns a NumPy array.

import numpy as np

lst = [0, 1, 100, 42, 13, 7]

print(np.array(lst))

The output is:

# [ 0 1 100 42 13 7]

This creates a new data structure in memory. Changes on the original list are not visible to the variable that holds the NumPy array:

lst = [0, 1, 100, 42, 13, 7]

a = np.array(lst)

lst.append(999)

print(a)

# [ 0 1 100 42 13 7]

The element 999 which is now part of list lst is not part of array a.

Method 2: np.asarray(…)

An alternative is to use the np.asarray() function that takes one argument—the iterable—and converts it to the NumPy array. The difference to np.array() is that it doesn’t create a new copy in memory IF you pass a NumPy array. All changes made on the original array are reflected on the NumPy array! So be careful.

lst = [0, 1, 100, 42, 13, 7]

a = np.array(lst)

b = np.asarray(a)

a[0] = 99

print(b)

# [ 99 1 100 42 13 7]

The array b is created using the np.asarray() function, so if you change a value of array a, the change will be reflected on the variable b (because they point to the same object in memory).

[Video] How to Convert a List of Lists to a NumPy Array?

Convert List of Lists to 2D Array

Problem: Given a list of lists in Python. How to convert it to a 2D NumPy array?

Example: Convert the following list of lists

[[1, 2, 3], [4, 5, 6]]

into a NumPy array

[[1 2 3] [4 5 6]]

Solution: Use the np.array(list) function to convert a list of lists into a two-dimensional NumPy array. Here’s the code:

# Import the NumPy library

import numpy as np # Create the list of lists

lst = [[1, 2, 3], [4, 5, 6]] # Convert it to a NumPy array

a = np.array(lst) # Print the resulting array

print(a) '''

[[1 2 3] [4 5 6]] '''

Try It Yourself: Here’s the same code in our interactive code interpreter:

<iframe height="700px" width="100%" src="https://repl.it/@finxter/numpylistoflists?lite=true" scrolling="no" frameborder="no" allowtransparency="true" allowfullscreen="true" sandbox="allow-forms allow-pointer-lock allow-popups allow-same-origin allow-scripts allow-modals"></iframe>

Hint: The NumPy method np.array() takes an iterable as input and converts it into a NumPy array.

Convert a List of Lists With Different Number of Elements

Problem: Given a list of lists. The inner lists have a varying number of elements. How to convert them to a NumPy array?

Example: Say, you’ve got the following list of lists:

[[1, 2, 3], [4, 5], [6, 7, 8]]

What are the different approaches to convert this list of lists into a NumPy array?

Solution: There are three different strategies you can use. (source)

(1) Use the standard np.array() function.

# Import the NumPy library

import numpy as np # Create the list of lists

lst = [[1, 2, 3], [4, 5], [6, 7, 8]] # Convert it to a NumPy array

a = np.array(lst) # Print the resulting array

print(a) '''

[list([1, 2, 3]) list([4, 5]) list([6, 7, 8])] '''

This creates a NumPy array with three elements—each element is a list type. You can check the type of the output by using the built-in type() function:

>>> type(a)

<class 'numpy.ndarray'>

(2) Make an array of arrays.

# Import the NumPy library

import numpy as np # Create the list of lists

lst = [[1, 2, 3], [4, 5], [6, 7, 8]] # Convert it to a NumPy array

a = np.array([np.array(x) for x in lst]) # Print the resulting array

print(a) '''

[array([1, 2, 3]) array([4, 5]) array([6, 7, 8])] '''

This is more logical than the previous version because it creates a NumPy array of 1D NumPy arrays (rather than 1D Python lists).

(3) Make the lists equal in length.

# Import the NumPy library

import numpy as np # Create the list of lists

lst = [[1, 2, 3], [4, 5], [6, 7, 8, 9]] # Calculate length of maximal list

n = len(max(lst, key=len)) # Make the lists equal in length

lst_2 = [x + [None]*(n-len(x)) for x in lst]

print(lst_2)

# [[1, 2, 3, None], [4, 5, None, None], [6, 7, 8, 9]] # Convert it to a NumPy array

a = np.array(lst_2) # Print the resulting array

print(a) '''

[[1 2 3 None] [4 5 None None] [6 7 8 9]] '''

You use list comprehension to “pad” None values to each inner list with smaller than maximal length.

Related Articles

• How to Convert a List of Lists to a NumPy array?
• What are Advantages of NumPy arrays over Python lists?

Where to Go From Here?

Enough theory, let’s get some practice!

To become successful in coding, you need to get out there and solve real problems for real people. That’s how you can become a six-figure earner easily. And that’s how you polish the skills you really need in practice. After all, what’s the use of learning theory that nobody ever needs?

Practice projects is how you sharpen your saw in coding!

Do you want to become a code master by focusing on practical code projects that actually earn you money and solve problems for people?

Then become a Python freelance developer! It’s the best way of approaching the task of improving your Python skills—even if you are a complete beginner.

Join my free webinar “How to Build Your High-Income Skill Python” and watch how I grew my coding business online and how you can, too—from the comfort of your own home.

Join the free webinar now!

Unity have just released Unity 2019.4 LTS, or Long Term Support.  This is a version of Unity that is only going to receive bug and security fixes going forward, making it the most stable and ideal version of Unity to start new Unity projects on.

Details on the 2019 LTS release from the Unity blog:

As part of our commitment to improving the development process for users, Unity is now shifting to offering LTS as the default version of the platform, and we have committed to doing fewer releases per year. You have been incredible in helping us understand your needs and we’re grateful for your feedback. In response to this we have improved, and will continue to improve, workflows and modernize Unity to be more flexible, focusing on delivering stability and interoperability of features.

Beginning today with the release of 2019 LTS, the LTS versions of Unity will become the default available for download from the Unity Hub. Moving forward, Unity will issue up to two TECH stream releases per year followed by the annual LTS release. The TECH Stream is for creators who demand to be on the cutting edge as technologies and workflows are evolving, while LTS is suggested for creators aiming to ship their projects in the near future, or for those who have everything they need in 2019 LTS. This shift in release philosophy will ensure that you are installing the most stable version for projects in production.

What’s in the 2019 LTS?

The new Long-Term Support (LTS) version of Unity contains everything from the previous three TECH stream releases with all the fixes and improvements we added to Unity 2019.3.0 since it was released. Similar to our previous LTS releases the focus for 2019 LTS isn’t new features, API changes or enhancements, but defect rectification and usability upgrades aimed at improving the stability of the product. In short, it’s a continuation of the 2019 TECH stream without new features which is why we also call it Unity 2019.4.0.

You can download Unity 2019.4 LTS in the Unity Hub or on the LTS support page here.  Learn more about Unity 2019.4LTS in the video below.

GameDev News Unity

This might sound a little wild but Sega could be working on a brand new Super Monkey Ball game.

In an email exchange (dated 6th April 2020) with YouTuber Nick Robinson, Brian Matt – the voice of the original announcer for the Super Monkey Ball games – revealed he had done “one paid recording” with Sega in his country of residence, Japan.

A more recent follow-up video interview with Robinson seems to suggest the recording was indeed for a new Monkey Ball.

As the voice actor is under a strict NDA, he couldn’t say much – but he was able to repeat some of the lines from his recording session with Sega. Here are a few:

I can give you what I can give you without getting in trouble, okay…”rank one”, “rank two”, “rank three” of course “goal” – that one never goes away. This was the new one – we did two takes on this one – “advanced level one”, “enhanced level one”

Later on in the interview, he was asked what the name or the title of this game might be. While the voice actor couldn’t confirm anything he did sum up his thoughts with the following comment:

they’re going to go with Super Monkey Ball and then one word, and it’s not going to be a number

Robinson has done a little extra detective work and believes when Brian shows the top half of Sega script, the three katakana characters on display sound like “retro” – leading to a theory that the title might be called Super Monkey Ball Retro.

The day after this interview, the voice actor shared “one last breadcrumb” via Instagram. In a post referencing Robinson, he tagged Sega, Sony, and a few others.

The two names at the very end, though, were perhaps the most interesting – Masao Shirosaki (who oversaw development on Super Monkey Ball: Banana Blitz HD) and Toshihiro Nagoshi (the Yakuza and Super Monkey Ball creator) – could they perhaps be in charge of this new project, if it is the real deal?

What do you make of all of this? Would you like to see a brand-new Super Monkey Ball game? Tell us down below.

It’s been a painfully quiet week in the Nintendo world – things have been much more exciting in the futuristic, wireless router-inspired land of PlayStation over the last couple of days – but that doesn’t mean we can’t still gather around and discuss our favourite hobby.

Members of Team Nintendo Life have discussed their weekend gaming plans below, and we’d love for you to join in via our poll and comment sections. Enjoy!

Gavin Lane, features editor

After seeing that Firewatch is on sale on the US eShop, I’ve decided I need to finish it. It’s hardly a massive game and after what personally felt like a very long week for some reason, settling down in the woods and getting back to nature sounds like just the ticket this weekend. You can’t beat the smell of those Douglas Firs.

Beyond that, I’d love to tool around some more with Streets of Rage 4. After beating the game on Normal (with Adam, who feels slightly OP, no?), I want to go back in and unlock some of the retro roster. It’s such a great game, and I’m hoping the music will have more of an effect on me as it becomes more familiar.

Austin Voigt, contributing writer

This weekend, I’m gonna dig into my backlog again (or at least, I plan to… but those plans rarely seem to work out). I’ve got some work to do in Good Job!, Picross S4, Little Town Hero, GRIS, Mario + Rabbids, Xenoblade Chronicles 2, and Luigi’s Mansion 3 are just a few of the games that I’ve started, but made little to no progress in since the launch of Animal Crossing. I’ve burned out a bit on New Horizons – as sad as I am to say it – and playing something else should hopefully refresh my zest for island life.

Ryan Craddock, news editor

As I touched upon last week, I’ve been spending a bit of time trying to make progress with my Pokémon Sword and Shield Pokédex recently ahead of the DLC’s arrival. I’ve just reached 350 out of the available 400, and apart from an odd few that require annoying trading requirements, I hope to get that number a little closer to the maximum this weekend.

Other than that, I’ll just be desperately trying to catch up on much-needed sleep. Because that’s what young adults do with their spare time, right?

Gonçalo Lopes, contributing writer

Yet another weekend saved by the deluge of Nindies landing on the eShop. Project Warlock is a fantastic throwback to all early FPS while Jump King lives up to its name with its unique and incredibly challenging game mechanic. A great racer gets its due sequel with Super Toy Cars 2 while my platforming dangling skills will be put to the test with the amazing Remnants of Naezith. Far more unexpected is the welcome arrival of two good strategy games: medieval RTS action with Ancestors Legacy and turn-based, morning cartoon mecha action with Warborn.

My game of the week is Arcade Archives Sunset Riders. Go ahead, bury me with my money.

As always, thanks for reading! Make sure to leave a vote in the poll above and a comment below with your gaming choices over the next few days…

• Destiny 2 is too large to efficiently update and maintain.
• The size and complexity of the game are also contributing to more bugs
  and less innovation.
• Instead of building a Destiny 3 and leaving D2 behind, each year, we
  are going to cycle older, less actively played content out of the live game and
  into what we’re calling the Destiny Content Vault (DCV).
• This will allow us to add to and support D2 for years, including the three
  new annual expansions we announced today, starting with Beyond Light this
  fall.
• The DCV will include all content from Destiny 1 and anything that
  cycles out from Destiny 2.
• We will bring back (or “unvault”) activity and destination content
  from the DCV each year.
• Unvaulting starts in D2 Year 4, with the Cosmodrome coming back, as
  well as its three strikes and the return of the Vault of Glass raid.
• The primary D2 content leaving the game and going into the DCV this
  fall are the destinations – Mars, Io, Titan, Mercury and Leviathan – and their supported
  activities.
• There will be new ways to earn the Exotics originally linked to content that
  has entered the DCV.
• When Beyond Light ships, the Director will have the following
  destinations:
• Europa (new)
• Cosmodrome (unvaulted)
• Moon
• Tangled Shore
• Dreaming City
• European Dead Zone
• Nessus
• This approach allows us respond to player feedback more rapidly,
  enable more innovation, and will keep Destiny 2 and your characters thriving for
  years to come.
• More details to come
  soon and throughout the year.

Earlier
today, we laid out a vision for Destiny’s future, built right inside of Destiny 2. A future where we maintain your
characters, accounts, and continuity with our game systems and build on each of
them for years. This fall ushers in a new era in Destiny’s journey, launching
off a trilogy of expansions where your Guardians will explore the true nature
of Light and Dark:

Put plainly, we are investing in Destiny 2 for years to come. But to
continue your Guardian’s journey and deliver on this roadmap, we need to make
some changes to our ever-growing world so it can flourish.

The Limits of Growth

Over the
past couple months, we’ve mentioned the problems that come with maintaining a
game the size of Destiny 2; and we’ve said that it cannot grow infinitely.
After three years of non-stop growth, the scope and complexity of Destiny 2 has
ballooned to unprecedented scale.

As of this
writing, Destiny 2 features nine destinations, 40 story missions, 54
adventures, 42 Lost Sectors, 17 strikes, 31 PvP maps, 12 one-off special
activities (like Menagerie or Zero Hour), seven raids, six Gambit arenas, three
dungeons, many, many
quests, patrols, public events, and of course, thousands of associated rewards.
All of that, plus hundreds of game systems which layer on top of that content.

This
unrelenting growth has resulted in a game that requires players to download up
to 115GB to play, as well as huge patches tied to frequent updates. And those numbers
are rising rapidly, as we’ve been adding approximately 25GB of content each
year to Destiny 2 since launch. Those sizes not only stress hard drive capacity
but also push the limits of patching capability. It also makes the time to
generate a stable update for the game after all content is finalized, tested, and ready to go balloon to literal days instead of hours.

Worse
still, that 115GB includes a lot of content that isn’t relevant anymore – and
can’t remain relevant – as we evolve the world and introduce new experiences
that will take center stage instead. For example: Warmind’s campaign represents
only 0.3% of all time played in Season of the Worthy and yet the Warmind
Expansion accounts for 5% of our total install size. This dramatic
imbalance between player engagement and overall cost to maintain is found in a lot
of our legacy content.

Impact on the Live Game

Our
ambition is for Destiny 2 to be the best Action MMO in the world and that means
being far more agile and nimble than we are today. But the simple fact is that our
game’s size and complexity prevents us from improving Destiny as fast as we –
and you – would like.

The “Destiny Content Vault”

To set a
new maintainable foundation for the game this fall and to create room for Beyond
Light and the future roadmap, the first Destiny 2 deposit into the DCV will
be larger than those to come in the future.

Curating the Vault

Going
forward, our explicit goal will be to try to keep the scope and scale of Destiny
2 at a relatively consistent size in order to increase our agility and to be
able to properly support and maintain the game. Over the course of each year,
the game’s content scope will grow as we add new destinations and activities in
our expansions and Seasons. As we approach the next expansion, another cycle of
content will go into the DCV to make way for a new influx of destinations and
activities.

We will
always do our best to give early notice of what’s being cycled into the DCV, to
help you and your friends plan around how you want to complete your collections
and build up your account before the new Destiny year starts. The vast majority
of content we choose to vault will also be from destinations and activities
that have been free for all players for several months prior to their
departure. For example: the Curse of Osiris campaign, which has been free since
Shadowkeep launched in October 2019, and part of the Destiny 2 experience since
December 2017, will go in the DCV later this year.

Year 4 Destiny Content Vault
Preview 

Here is an early
preview of some of what’s going into the Destiny Content Vault (DCV) and what’s
returning in Year 4.

Returning from the DCV

– Destiny 2
Dev Team

We draw closer to the release of the Nether Update.  We see some fixes for some more of those pesky crashes as well some hang-ups when trying to open certain words.

Remember that only those on Xbox One / Windows 10 / and Android may participate in the Beta builds.  You will not be able to join Realms or non-beta players worlds and you will not be able to open worlds opened in the Beta in earlier/current stable builds of Bedrock.

Performance and Stability

• Fixed several crashes that could occur during gameplay
• Fixed a crash that could occur when attempting to create world with the Tropical City Resort mash-up pack
• Fixed an issue that could cause a hang on start up when trying to open certain worlds

General

• Fixed an issue with projectiles being destroyed prematurely if they didn’t deal damage. This is now optional with the addition of 2 new flags to the projectile

Gameplay

• Fixed an issue that could cause chests to generate without loot MCPE-69003

Graphical

• Fixed rendering issues while riding a mount

Add-Ons and Scripting

• Fixed an issue that could occur when the movement component is removed, meaning that a mob’s speed has to ramp up from 0 again
• Changes to components: set_last_hurt_requires_damage and destroy_on_hit_requires_damage. Each defaulting to true to respect old behavior, but can now be set to false if it is desired to have a projectile that is destroyed even when it doesn’t deal damage

Commands

• Added new overload for /replaceitem with an option for destroy (the old behavior) or keep (the command will return an error if an item occupies that slot)
• Fixed a bug where a mob wouldn’t delete its goal if all goals were trying to be removed
• Fixed spamming of particles, sounds, and events for looped, non-zero-length animations with timelines
• Fixed a syntax error issue when running the /xp command with levels
• Fixed an issue with “A Nightmare in Candyland” map which was no longer teleporting players correctly