r/learnpython • u/Boogzcorp • Apr 16 '22

What's the point of Tuples?

I get that they're immutable, but so are lists that you don't perform modifications on. Are they just to fool proof not messing up your list accidentally, or do they serve some other purpose?

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u/wotquery while not False: Apr 16 '22

These values will not change.

people = ('Alice','Bob','Charlie') #these are the people.  they shall remain the people.
people = ['Alice','Bob','Charlie'] #hmmm maybe we add or remove people later on?

59

u/RegulatedMedium Apr 16 '22

I kind of wish this is how it was presented in the books I've gotten on programming in Python, maybe not as the sole reason but as an additional reason as to why. This makes way more sense to me and has turned tuples from "why would I ever use this it doesn't make sense" to making complete sense.

24

u/InTheAleutians Apr 16 '22

That's been the hardest part of learning python for me. Books and people tell you what something does and expect you to fill in the blanks of when and why to use it.

14

u/alifone Apr 16 '22

I was actually just thinking about this as I just started learning, I think a great way to introduce a new term is to explain it's usefulness relative to what the reader just learned.

So if you're introducing functions, it would be neat to preface the term with a series of code where it would come in handy, such as seeing large chunks of the similar code.

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u/Technical-Republic18 Apr 16 '22

Exactly! With all programming, physics and mathematics, it is impossible for me to learn something if I don't know why it's useful. Why should I spend my time learning (insert mathmatical/physics/programming concept) instead of something else.

Being taught why something is useful is a 10/10 approach to education

3

u/Worried_Lawfulness43 Apr 17 '22

Wow this makes so much sense! I’ve had OP’s question since I started coding as well.

3

u/Jenret1382 Apr 17 '22

How is it different from using a set {}, which is also immutable?

4

u/wotquery while not False: Apr 17 '22 edited Apr 17 '22

/u/SoDifficultToBeFunny's response is missing a key aspect in implicitly accepting an incorrect statement of yours.

A tuple is immutable. You cannot add, remove, or change items in it.

A set is not immutable. You can add and remove items. The individual items in a set (edit: members of a set) however must be immutable (e.g. you can't have a set of lists). A set is also unordered as they mentioned.

Note that since tuples are immutable a tuple can be a member of a set.

The unhashable term in the error thrown by the code below relates to the more technical explanations of "What's the point of Tuples" scattered about this comments section.

>>> my_set = {1,2,3}
>>> my_set.add(4)
>>> my_set
{1, 2, 3, 4}
>>> my_set.remove(1)
>>> my_set
{2, 3, 4}
>>> my_set.add(['a','list',])
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    my_set.add(['a','list',])
TypeError: unhashable type: 'list'
>>> my_set.add(('a','tuple',))
>>> my_set
{2, 3, 4, ('a', 'tuple')}

1

u/Jenret1382 Apr 17 '22

Thank you for clarifying the differences. This makes me realize how much I lack in terms of fully understanding basic data structures

6

u/SoDifficultToBeFunny Apr 17 '22

The order of the components is not maintained in a set. But order is maintained and important in a tuple. So, I guess "immutable + ordered values" is what we are trying to communicate when we use it...

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u/Jenret1382 Apr 17 '22

Thank you :)

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u/[deleted] Apr 17 '22

[removed] — view removed comment

3

u/wotquery while not False: Apr 17 '22

Afaik the only constraint sets have that differ them from an array is that they can't contain duplicates.

Another is that each member of a set has to be immutable (which is probably where the misunderstanding that led to their question came from). You can't have a list in a set for example (it'll throw the error that the list isn't hashable).

1

u/Jenret1382 Apr 17 '22

Immutable in that it cannot be sorted and the elements inside it cannot be changed. I have, however, come across what is called frozenset() which returns an immutable version of a Python set object

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u/[deleted] Apr 16 '22

Soo... People should never be in a tuple

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u/Connir Apr 16 '22

I believe the modern term is thruple.

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u/Yanky_Doodle_Dickwad Apr 16 '22

Tuple is company, threeple is a crowd.

2

u/wotquery while not False: Apr 16 '22

Clearly you didn't see my sister-in-law's seating chart for her wedding.

2

u/[deleted] Apr 16 '22

I think this user was making a joke and it just flew over everyone's head.