By Ian Boudreau 20 Feb 2020

Update (Thu 20th Feb, 2020 17:30 GMT): As a reminder, both Sonic The Hedgehog 2 and Puyo Puyo 2 have launched on Nintendo Switch today. Sega has shared a brand new trailer to celebrate, and we thought it’d be rude not to share it with you lovely lot. Enjoy!

Original Article (Fri 7th Feb, 2020 10:45 GMT): Nintendo Switch’s Sega Ages range is about to have one of its finest days so far with both Sonic The Hedgehog 2 and Puyo Puyo 2 set to launch simultaneously. You’ll be able to play both of these games on Nintendo’s platform starting 20th February.

The Switch version of Sonic The Hedgehog 2 will feature the return of its competitive two-player mode, newly-added features like Sonic Mania‘s ‘drop dash’ (where you spin dash in mid-air to quickly gain speed) and Super Sonic Mode, as well as Time Trials, online rankings, and even Knuckles the Echidna.

Puyo Puyo 2 is also being treated to some welcome additions such as a full English localisation, two-player online battles, online rankings, a quick rewind function, and a colourblind mode. Here are official descriptions of both titles:

About Sonic The Hedgehog 2
Hailed as one of the most successful games for the Genesis (Mega Drive), Sonic The Hedgehog 2 garnered critical acclaim swiftly after its 1992 release. Follow Sonic and Tails (in his series debut!) as they team up against the nefarious Dr. Eggman in order to save the Chaos Emeralds from the clutches of evil.

About Puyo Puyo 2
Puyo Puyo 2 (also known as Puyo Puyo Tsu) is considered one of the biggest arcade games of all time in Japan. This sequel introduced an improved ruleset along with the ability to offset Garbage Puyo sent by your opponent by creating Puyo chains of your own. Swap between Single Puyo Puyo, Double Puyo Puyo, and Endless Puyo Puyo game modes for even more Puyo fun in this classic puzzle experience.

Sonic The Hedgehog 2 and Puyo Puyo 2 will be available to download individually from 20th February for $7.99 a pop.

Excited for these new additions to the Sega Ages lineup? Let us know if you’ll be buying either (or both!) of these with a comment below.

Ready to earn the black belt of your regex superpower? This tutorial shows you the subtle but important difference between greedy and non-greedy regex quantifiers.

But first things first: what are “quantifiers” anyway? Great question – I’m glad you asked! So let’s dive into Python’s three main regex quantifiers.

Python Regex Quantifiers

The word “quantifier” originates from latin: it’s meaning is quantus = how much / how often.

This is precisely what a regular expression quantifier means: you tell the regex engine how often you want to match a given pattern.

If you think you don’t define any quantifier, you do it implicitly: no quantifier means to match the regular expression exactly once.

So what are the regex quantifiers in Python?

Note that in this tutorial, I assume you have at least a remote idea of what regular expressions actually are. If you haven’t, no problem, check out my detailed regex tutorial on this blog.

You see in the table that the quantifiers ?, *, +, {m}, and {m,n} define how often you repeat the matching of regex A.

Let’s have a look at some examples—one for each quantifier:

>>> import re

>>> re.findall('a?', 'aaaa')

['a', 'a', 'a', 'a', '']

>>> re.findall('a*', 'aaaa')

['aaaa', '']

>>> re.findall('a+', 'aaaa')

['aaaa']

>>> re.findall('a{3}', 'aaaa')

['aaa']

>>> re.findall('a{1,2}', 'aaaa')

['aa', 'aa']

In each line, you try a different quantifier on the same text 'aaaa'. And, interestingly, each line leads to a different output:

• The zero-or-one regex 'a?' matches four times one 'a'. Note that it doesn’t match zero characters if it can avoid doing so.
• The zero-or-more regex 'a*' matches once four 'a's and consumes them. At the end of the string, it can still match the empty string.
• The one-or-more regex 'a+' matches once four 'a's. In contrast to the previous quantifier, it cannot match an empty string.
• The repeating regex 'a{3}' matches up to three 'a's in a single run. It can do so only once.
• The repeating regex 'a{1,2}' matches one or two 'a's. It tries to match as many as possible.

You’ve learned the basic quantifiers of Python regular expressions. Now, it’s time to explore the meaning of the term greedy. Shall we?

Python Regex Greedy Match

A greedy match means that the regex engine (the one which tries to find your pattern in the string) matches as many characters as possible.

For example, the regex 'a+' will match as many 'a's as possible in your string 'aaaa'. Although the substrings 'a', 'aa', 'aaa' all match the regex 'a+', it’s not enough for the regex engine. It’s always hungry and tries to match even more.

In other words, the greedy quantifiers give you the longest match from a given position in the string.

As it turns out, all default quantifiers ?, *, +, {m}, and {m,n} you’ve learned above are greedy: they “consume” or match as many characters as possible so that the regex pattern is still satisfied.

Here are the above examples again that all show how greedy the regex engine is:

>>> import re

>>> re.findall('a?', 'aaaa')

['a', 'a', 'a', 'a', '']

>>> re.findall('a*', 'aaaa')

['aaaa', '']

>>> re.findall('a+', 'aaaa')

['aaaa']

>>> re.findall('a{3}', 'aaaa')

['aaa']

>>> re.findall('a{1,2}', 'aaaa')

['aa', 'aa']

In all cases, a shorter match would also be valid. But as the regex engine is greedy per default, those are not enough for the regex engine.

Okay, so how can we do a non-greedy match?

Python Regex Non-Greedy Match

A non-greedy match means that the regex engine matches as few characters as possible—so that it still can match the pattern in the given string.

For example, the regex 'a+?' will match as few 'a's as possible in your string 'aaaa'. Thus, it matches the first character 'a' and is done with it. Then, it moves on to the second character (which is also a match) and so on.

In other words, the non-greedy quantifiers give you the shortest possible match from a given position in the string.

You can make the default quantifiers ?, *, +, {m}, and {m,n} non-greedy by appending a question mark symbol '?' to them: ??, *?, +?, and {m,n}?. they “consume” or match as few characters as possible so that the regex pattern is still satisfied.

Here are some examples that show how non-greedy matching works:

Non-Greedy Question Mark Operator (??)

Let’s start with the question mark (zero-or-one operator):

>>> import re

>>> re.findall('a?', 'aaaa')

['a', 'a', 'a', 'a', '']

>>> re.findall('a??', 'aaaa')

['', 'a', '', 'a', '', 'a', '', 'a', '']

In the first instance, you use the zero-or-one regex 'a?'. It’s greedy so it matches one 'a' character if possible.

In the second instance, you use the non-greedy zero-or-one version 'a??'. It matches zero 'a's if possible. Note that it moves from left to right so it matches the empty string and “consumes” it. Only then, it cannot match the empty string anymore so it is forced to match the first 'a' character. But after that, it’s free to match the empty string again. This pattern of first matching the empty string and only then matching the 'a' if it is absolutely needed repeats. That’s why this strange pattern occurs.

Non-Greedy Asterisk Operator (*?)

Let’s start with the asterisk (zero-or-more operator):

>>> re.findall('a*', 'aaaa')

['aaaa', '']

>>> re.findall('a*?', 'aaaa')

['', 'a', '', 'a', '', 'a', '', 'a', '']

First, you use the zero-or-more asterisk regex 'a*'. It’s greedy so it matches as many 'a' characters as it can.

Second, you use the non-greedy zero-or-one version 'a*?'. Again, it matches zero 'a's if possible. Only if it has already matched zero characters at a certain position, it matches one character at that position, “consumes” it, and moves on.

Non-Greedy Plus Operator (+?)

Let’s start with the plus (one-or-more operator):

>>> re.findall('a+', 'aaaa')

['aaaa']

>>> re.findall('a+?', 'aaaa')

['a', 'a', 'a', 'a']

First, you use the one-or-more plus regex 'a+'. It’s greedy so it matches as many 'a' characters as it can (but at least one).

Second, you use the non-greedy one-or-more version 'a+?'. In this case, the regex engine matches only one character 'a', consumes it, and moves on with the next match.

Let’s summarize what you’ve learned so far:

Greedy vs Non-Greedy Match – What’s the Difference?

Given a pattern with a quantifier (e.g. the asterisk operator) that allows the regex engine to match the pattern multiple times.

A given string may match the regex in multiple ways. For example, both substrings 'a' and 'aaa' are valid matches when matching the pattern 'a*' in the string 'aaaa'.

So the difference between the greedy and the non-greedy match is the following: The greedy match will try to match as many repetitions of the quantified pattern as possible. The non-greedy match will try to match as few repetitions of the quantified pattern as possible.

Examples Greedy vs Non-Greedy Match

Let’s consider a range of examples that help you understand the difference between greedy and non-greedy matches in Python:

>>> import re

>>> re.findall('a+', 'aaaa')

['aaaa']

>>> re.findall('a+?', 'aaaa')

['a', 'a', 'a', 'a']

>>> re.findall('a*', 'aaaa')

['aaaa', '']

>>> re.findall('a*?', 'aaaa')

['', 'a', '', 'a', '', 'a', '', 'a', '']

>>> re.findall('a?', 'aaaa')

['a', 'a', 'a', 'a', '']

>>> re.findall('a??', 'aaaa')

['', 'a', '', 'a', '', 'a', '', 'a', '']

Make sure you completely understand those examples before you move on. If you don’t, please read the previous paragraphs again.

Which is Faster: Greedy vs Non-Greedy?

Considering that greedy quantifiers match a maximal and non-greedy a minimal number of patterns, is there any performance difference?

Great question!

Indeed, some benchmarks suggest that there’s a significant performance difference: the greedy quantifier is 100% slower in realistic experiments on benchmark data.

So if you optimize for speed and you don’t care about greedy or non-greedy matches—and you don’t know anything else—go for the non-greedy quantifier!

However, the truth is not as simple. For example, consider the following basic experiment that falsifies the previous hypothesis that the non-greedy version is faster:

>>> import timeit

>>> timeit.timeit('import re;re.findall("a*", "aaaaaaaaaaaa")')

1.0579840000000331

>>> timeit.timeit('import re;re.findall("a*?", "aaaaaaaaaaaa")')

3.7830938000000742

I used the speed testing tool timeit that allows to throw in some simple Python statements and check how long they run. Per default, the passed statement is executed 1,000,000 times.

You can see a notable performance difference of more than 300%! The non-greedy version is three times slower than the greedy version.

Why is that?

The reason is the re.findall() method that returns a list of matching substrings. Here’s the output both statements would produce:

>>> re.findall("a*", "aaaaaaaaaaaa")

['aaaaaaaaaaaa', '']

>>> re.findall("a*?", "aaaaaaaaaaaa")

['', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '', 'a', '']

You can see that the greedy version finds one match and is done with it. The non-greedy version finds 25 matches which leads to far more processing and memory overhead.

So what happens if you use the re.search() method that returns only the first match rather than the re.findall() method that returns all matches?

>>> timeit.timeit('import re;re.search("a*", "aaaaaaaaaaaa")')

0.8420328999998219

>>> timeit.timeit('import re;re.search("a*?", "aaaaaaaaaaaa")')

0.7955709000000297

As expected, this changes things again. Both regex searches yield a single result, but the non-greedy match is much shorter: it matches the empty string '' rather than the whole string 'aaaaaaaaaaaa'. Of course, this is a bit faster.

However, the difference is negligible in this minimal example.

There’s More: Greedy, Docile, Lazy, Helpful, Possessive Match

In this article, I’ve classified the regex world into greedy and non-greedy quantifiers. But you can differentiate the “non-greedy” class even more!

Next, I’ll give you a short overview based on this great article of the most important terms in this regard:

• Greedy: match as many instances of the quantified pattern as you can.
• Docile: match as many instances of the quantified pattern as long as it still matches the overall pattern—if this is possible. Note that what I called “greedy” in this article is really “docile”.
• Lazy: match as few instances of the quantified pattern as needed. This is what I called “non-greedy” in this article.
• Possessive: never gives up a partial match. So the regex engine may not even find a match that actually exist—just because it’s so greedy. This is very unusual and you won’t see it a lot in practice.

If you want to learn more about those, I’d recommend that you read this excellent online tutorial.

Where to Go From Here

Summary: You’ve learned that the greedy quantifiers ?, *, and + match as many repetitions of the quantified pattern as possible. The non-greedy quantifiers ??, *?, and +? match as few repetitions of the quantified pattern as possible.

If you want to master Python and regular expressions, join my free email academy—it’s fun!

Google Summer of Code 2020 organizations have just be announced.  Every year since 2005, Google have sponsored the Summer of Code, an opportunity for university students around the world to contribute to open source projects and get paid.  In this years list of recipients, there are a few related to game development, including:

As well as dozens of prominent open source projects including several programming languages such as Lua and Dart and plenty more.  Both Godot and Blender participated last year and it directly resulted in several improvements throughout the year.

If you are a student interested in signing up, that process begins March 16th and you can learn more in the FAQ available here.  Learn more in the video below.

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GameDev News Programming

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By Christine McKee
Thursday, February 20, 2020, 09:08 pm PT (12:08 am ET)

Apple iPhone users looking to make the switch to 5G can now pre-order Samsung Galaxy S20 devices with aggressive iPhone trade-in values and even free gift offers.

Samsung launches S20 5G phones

With Apple’s rumored 5G iPhone launching in September, users wanting to experience 5G regardless of operating system (subject to carrier availability) can pre-order Samsung’s new Galaxy S20 devices, including the S20, S20+ and S20 Ultra 5G, at leading retailers. Further incentivizing iOS users to make the switch to Android, Samsung is offering shoppers up to $200 in Samsung credit in addition to trade-in deals of up to $700.

Here at AppleInsider, we’ll be testing the new 5G S20 smartphones, putting them through the paces against Apple’s current iPhone offerings. But for those looking to get their hands on an S20 asap, here are the best deals on the new 5G phones.

Samsung Galaxy S20, S20+ and S20 Ultra 5G pre-orders

• B&H: Get up to $200 in Samsung credit. Plus, free 2-day shipping within the contiguous U.S. and a sales tax refund in qualifying states with the Payboo Card.
• Amazon: Free Galaxy Buds and Wireless Charger Duo Pad with Galaxy S20 5G devices.
• Samsung: Get up to $200 Samsung credit when you pre-order select Galaxy S20 models. Plus, get up to $700 in trade-in value on iPhones.
• Best Buy: Save up to $850 on the new Samsung Galaxy S20 5G, S20+ 5G or S20 Ultra 5G with pre-order, qualified activation and trade-in. Plus, get up to a $200 Samsung credit.

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Additional Apple deals

AppleInsider and Apple authorized resellers are also running additional exclusive savings on Apple hardware that will not only deliver the lowest prices on many of the items, but also throw in bonus discounts on AppleCare, peripherals and more. These deals are as follows:

Interested in additional Apple hardware? See if there is a Mac, iPad or Apple Watch deal that will save you $100s by checking out prices.appleinsider.com.

This Week at Bungie, we’re calling in reservations.

The first three Empyrean Foundation goals have been met with haste. One billion Fractaline isn’t enough for the Foundation, and the next goal is currently in reach. Your next stop: 2.2 Billion Fractaline donations.

We knew you’d rise to the challenge, but this? This is absolutely insane. Keep that Fractaline coming. We’re seeing quite a few Guardians investing in their Fractaline futures, but many hitting the donation button to quickly earn some sweet Timelost weapons.

Now, let’s look at the calendar. We have some beats to cover that are coming up quick, with a new Season on the way in just over a month! Below, you’ll find details on Crimson Days, Destiny 2 Hotfix 2.7.1.1, and a patch note preview for Season 10.

Love is almost in the air

Have you been feeling a bit lonely lately? Lacking a partner by your side in the heat of battle? Crimson Days is on approach, bringing the perfect opportunity for you to form an unbreakable Crimson Bond with a fellow Guardian.

[youtube https://www.youtube.com/watch?v=9ylerb7niFQ?wmode=transparent&rel=0&fs=1&w=1136&h=641]

Crimson Doubles returns to the Crucible during the event, bringing explosive 2v2 combat to the fold. Stay close to your partner: you’ll each have heightened ability regen as long as you retain your Crimson Bond. If you stray too far away from each other, opponents will be able to see your every move. If you’d rather take your partner out for a stroll in one of Destiny 2’s PvE activities, Shaxx will offer bounties for you to complete in a two-person fireteam.

As you complete Crimson Doubles matches and bounties, you and your partner will be showered in delicious candy hearts. To sweeten the deal, Daily and Weekly bounties will offer double XP. Bright Dust will also be rewarded when completing your weekly bounties.

As you begin to stockpile Confectionary Hearts, they can be exchanged with Lord Shaxx for Crimson Days themed rewards, including two new Exotic Sparrows. Ride in tandem to show the strength of your Crimson Bond!

If this is your first Crimson Days event, or you didn’t earn enough hearts in years past, rewards from previous events will also be available to earn alongside the new Sparrows.

Eververse will feature many items from previous events for Bright Dust, including two new items exclusive to Crimson Days. One new item will be available for Silver only, the Heartfelt Union Multiplayer Emote.

Here’s the emote in action:

Crimson Days will be available from February 11 to February 18, 2020.

Cutting Edge

We’re a little over a month out from the next Season of Destiny 2 and this seems like a good time to start talking about Sandbox. Over the next few weeks, we’ll be covering upcoming changes to weapons and abilities. Some changes will be PvP-centric, while others will bear more of a PvE focus.

Our first subject: Swords.

Some are sharp. Some are blunt. One lets you bend space and time to teleport through enemies. Another has projectiles that can take down foes at range. Since the launch of Destiny 2, we’ve been seeing feedback on general functionality and the team has been kicking around ideas on how to make things a bit more enticing.

After some brainstorming and development time, Swords are receiving a sort of tableflip when it comes to light attacks, heavy attacks, and guarding. While you’ll still rip and tear through opponents, as you would expect from a Sword, most of what you know needs to be unlearned. The blades have been rebalanced, and a new energy meter is making its way to swords. Below, you’ll find a full rundown from our development team.

Dev Team: Swords are getting a little more love this Season. While Swords have been a staple of Destiny ever since their introduction in The Taken King, we felt they were due for an update both to freshen them up, but also to allow us more room to work with them in later releases.

Sword Energy

• Swords now have their own reserve of energy that recharges naturally on its own, and is not to be confused with ammo capacity. This energy will overtake your melee slot while you’re wielding a sword and is spent on various actions.

Guarding

• Guarding now uses sword energy instead of consuming ammo. Different guards have different consumption rates, damage resistance and behaviors, so be sure to experiment and find a guard type you like. You’ll still need at least one ammo to begin guarding, though.
• Back during Season of the Drifter, the Stronghold exotic for Titans was introduced, allowing them to guard with relative impunity and opening up a more interesting opportunities for swords to shine in a variety of content which caused us to take another look at the guard function itself. Although the guard function has always existed, it was never really considered worth the cost. With this change, we hope that players will use their guard intelligently to protect themselves instead of it being an almost unused button. Rest easy, Stronghold has also been modified to still allow Titans a unique guarding experience.

Light Attacks

• Grounded light attacks for all Swords will now loop for an infinite combo, and all Swords can cleave.
• While the basic three hit combo is quite a staple of melee weapons in many games – In a shooter this leaves the player extremely open to enemies. By letting the light attacks loop, we also push them and the heavy attacks apart further. Cleaving on light attacks was previously only on the Aggressive Swords, but we opted to add it to the rest of them for more hack ‘n slash.

Heavy Attacks

• Heavy attacks now consume Sword energy. While you are always able to perform a heavy attack, the attack is stronger when you have full energy, and weaker when you don’t.
• A lot of swordplay in many situations simply boiled down to endlessly mashing the heavy attack button instead of mixing up attacks which wasn’t quite the most interesting experience. Do note that aerial heavy attacks as a general rule do not consume Sword energy, but that can vary based on the Sword.

Shield Bypass

• A portion of most Sword attacks can partially bypass elemental shields.
• We added this to give Swords a little bit of a personality difference from shotguns who share a very similar role in combat as powerful CQC  weapons.

In general, Swords have also had some of the damage amounts for different attacks changed, and the various Sword perks have been adjusted. So you’ll want to experiment a bit after the changes hit. We do hope you’ll enjoy the changes.

Blinded by the Light

Hotfix after Hotfix, Destiny Player Support is here for you. Timetables, known issues, and frequently asked questions are handled with care. They approach each conversation with white gloves and gold standards.

This is their report.

CONTRIBUTING TO EMPYREAN RESTORATION

On Tuesday, the Empyrean Restoration went live. Player Support noticed that some players were confused on how to participate and contribute their Polarized Fractaline. To do so, players must complete the Bright Light quest from Saint-14. To unlock this quest, players must complete the following prerequisites:

CRIMSON DAYS AHEAD

Next week, Crimson Days returns to the Crucible. Our Help article will update on February 11, 2020, to bring you updated information about the event, including that it will end at the weekly reset on February 18.

Here are a few known issues about the event:

HOTFIX 2.7.1.1 AND RESOLVED ISSUES

Next Tuesday, February 11, we will release Destiny 2 Hotfix 2.7.1.1. This update will resolve some issues currently affecting players. Here is another preview of some of the issues that will be resolved:

Additionally, here’s the timeline for the Destiny 2 Hotfix 2.7.1.1 release on Tuesday:

CURRENT KNOWN ISSUES

While we continue investigating various known issues, here is a list of the latest issues that were reported to us in our #Help Forum:

For a full list of emergent issues in Destiny 2, players can review our Known Issues article. Players who observe other issues should report them to our #Help forum.

Variety

Over the years, there have been quite a few “metas” in Destiny 2. Different Legendary weapons will take the spotlight from time to time, sometimes usurped by a truly Exotic underdog. This week, our winner brings a montage using every exotic in the game.

Movie of the Week: SoaR-ing

[youtube https://www.youtube.com/watch?v=V8gMSBglqis?wmode=transparent&rel=0&fs=1&w=1136&h=641]

Honorable Mention: Guardian Bowl LIV

[youtube https://www.youtube.com/watch?v=HtW0dx0y6ro?wmode=transparent&rel=0&fs=1&w=1136&h=641]

I can’t wait to see what combinations you cook up. Have a great weekend, and we’ll see you next time.

Cheers,

Dmg04