Connect and share knowledge within a single location that is structured and easy to search. Apart from tuples being immutable there is also a semantic distinction that should guide their usage.
Tuples are heterogeneous data structures i. Tuples have structure, lists have order. You can then use this as a key in a dictionary to store notes on locations. A list on the other hand could be used to store multiple locations. Naturally one might want to add or remove locations from the list, so it makes sense that lists are mutable. On the other hand it doesn't make sense to add or remove items from an existing location - hence tuples are immutable.
There might be situations where you want to change items within an existing location tuple, for example when iterating through the lines of a page. But tuple immutability forces you to create a new location tuple for each new value. This seems inconvenient on the face of it, but using immutable data like this is a cornerstone of value types and functional programming techniques, which can have substantial advantages.
There are some interesting articles on this issue, e. The official Python documentation also mentions this. In a statically typed language like Haskell the values in a tuple generally have different types and the length of the tuple must be fixed. In a list the values all have the same type and the length is not fixed.
So the difference is very obvious. Finally there is the namedtuple in Python, which makes sense because a tuple is already supposed to have structure. This underlines the idea that tuples are a light-weight alternative to classes and instances.
Due to the smaller size of a tuple operation, it becomes a bit faster, but not that much to mention about until you have a huge number of elements.
That also means that you can't delete an element or sort a tuple. However, you could add a new element to both list and tuple with the only difference that since the tuple is immutable, you are not really adding an element but you are creating a new tuple, so the id of will change.
If you went for a walk, you could note your coordinates at any instant in an x,y tuple. If you wanted to record your journey, you could append your location every few seconds to a list.
The key difference is that tuples are immutable. This means that you cannot change the values in a tuple once you have created it. From docs. Tuples are immutable, and usually contain an heterogeneous sequence of elements that are accessed via unpacking see later in this section or indexing or even by attribute in the case of namedtuples.
Lists are mutable, and their elements are usually homogeneous and are accessed by iterating over the list. It's been mentioned that the difference is largely semantic: people expect a tuple and list to represent different information.
But this goes further than a guideline; some libraries actually behave differently based on what they are passed. Take NumPy for example copied from another post where I ask for more examples :.
The point is, while NumPy may not be part of the standard library, it's a major Python library, and within NumPy lists and tuples are completely different things. Python lists and tuples are similar in that they both are ordered collections of values. Besides the shallow difference that lists are created using brackets "[ This gives rise to differences in how they can or can't be used enforced a priori by syntax and differences in how people choose to use them encouraged as 'best practices,' a posteriori, this is what smart programers do.
The main difference a posteriori in differentiating when tuples are used versus when lists are used lies in what meaning people give to the order of elements. For tuples, 'order' signifies nothing more than just a specific 'structure' for holding information. What values are found in the first field can easily be switched into the second field as each provides values across two different dimensions or scales.
For lists, 'order' signifies a sequence or a directionality. The second element MUST come after the first element because it's positioned in the 2nd place based on a particular and common scale or dimension.
There are countless examples of people in popular culture and programmers who don't conform to these differences and there are countless people who might use a salad fork for their main course. At the end of the day, it's fine and both can usually get the job done. So, if you want the first 3 values of a given list or tuple, the syntax would be the same:. No further attention is paid to subsequent elements after earlier elements show a difference.
Mutability - Elements in a given list are mutable, elements in a given tuple are NOT mutable. Hashtables Dictionaries - As hashtables dictionaries require that its keys are hashable and therefore immutable, only tuples can act as dictionary keys, not lists. Homo vs. Heterogeneity of Elements - Generally list objects are homogenous and tuple objects are heterogeneous. Looping vs. The values of list can be changed any time but the values of tuples can't be change.
The advantages and disadvantages depends upon the use. If you have such a data which you never want to change then you should have to use tuple, otherwise list is the best option. We use parenthesis to construct tuples and square brackets [ ] to get a new list. Tuples are immutable, while lists are mutable. This point is the base the for the following ones. You can add a new element to both tuples and lists with the only difference that the id of the tuple will be changed i.
Tuples are hashable and lists are not. It means that you can use a tuple as a key in a dictionary. The list can't be used as a key in a dictionary, whereas a tuple can be used. This point is more about best practice. You should use tuples as heterogeneous data structures, while lists are homogenous sequences.
As people have already answered here that tuples are immutable while lists are mutable, but there is one important aspect of using tuples which we must remember. If the tuple contains a list or a dictionary inside it, those can be changed even if the tuple itself is immutable.
This happens because list and dictionary are the objects and these objects are not changing, but the contents its pointing to. The PEP -- Type Hints says that the types of elements of a tuple can be individually typed; so that you can say Tuple[str, int, float] ; but a list , with List typing class can take only one type parameter: List[str] , which hints that the difference of the 2 really is that the former is heterogeneous, whereas the latter intrinsically homogeneous.
Also, the standard library mostly uses the tuple as a return value from such standard functions where the C would return a struct. To reduce memory fragmentation and speed up allocations, Python reuses old tuples. If a tuple no longer needed and has less than 20 items instead of deleting it permanently Python moves it to a free list.
A free list is divided into 20 groups, where each group represents a list of tuples of length n between 0 and Each group can store up to 2 tuples. The first zero group contains only 1 element and represents an empty tuple.
In the example above we can see that a and b have the same id. That is because we immediately occupied a destroyed tuple which was on the free list. Since lists can be modified, Python does not use the same optimization as in tuples. However, Python lists also have a free list, but it is used only for empty objects.
If an empty list is deleted or collected by GC, it can be reused later. Why tuples are efficient than lists? The most important difference is time! When you do not want to change the data inside the list better to use tuple! Here is the example why use tuple! Start Learning Python.
Explore Python Examples. Related Topics Python tuple. Python Lists Vs Tuples In this article we will learn key differences between the List and Tuples and how to use these two data structure. Syntax Differences Syntax of list and tuple is slightly different. Example 1. In python we have type function which gives the type of object created. Example 2. Share on:. Did you find this article helpful? Sorry about that. How can we improve it?
Leave this field blank. Related Tutorials. Python Library Python tuple. Python Tutorial Python Tuple. Change Language. Related Articles. Table of Contents. Save Article. Improve Article. Like Article. List and Tuple in Python are the class of data structure.
The list is dynamic, whereas the tuple has static characteristics. List is just like the arrays, declared in other languages.
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