Tuples are immutable and cannot be deleted.
Dictionary can return the list of tuples by calling items, where each tuple is a key value pair.We must use tuple as the key if we need to create a composite key to use in a dictionary.A comparison operator in Python can work with tuples.In packing, we place value into a new tuple while in unpacking we extract those values back into variables.Python has tuple assignment feature which enables you to assign more than one variable at a time. If you have data that is immutable, implementing it as tuple will guarantee that it remains write-protected.Tuples that consist of immutable elements can be used as key for dictionary, which is not possible with list.Iterating through tuple is faster than with list, since tuples are immutable.To perform different task, tuple allows you to use many built-in functions like all(), any(), enumerate(), max(), min(), sorted(), len(), tuple(), etc.
Here is the Python 2 Code for all above example tup1 = ('Robert', 'Carlos','1965','Terminator 1995', 'Actor','Florida') The output of this code will be (‘c’, ‘e’). Slicing is not only applicable to tuple but also for array and list. To fetch specific sets of sub-elements from tuple or list, we use this unique function called slicing. But deleting tuple entirely is possible by using the keyword del Slicing of Tuple You cannot delete or remove items from a tuple. Tuples are immutable and cannot be deleted. It assigns the elements of each tuple to last and first and then prints the name and corresponding telephone number.ĭictionary can return the list of tuples by calling items, where each tuple is a key value pair. This loop navigates the keys in the directory, which are tuples. for last, first in directory: print first, last, directory We could use tuple assignment in a for loop to navigate this dictionary. Inside the brackets, the expression is a tuple. Assuming that we have declared the variables as last and first number, we could write a dictionary assignment statement as shown below: directory = number Since tuples are hashable, and list is not, we must use tuple as the key if we need to create a composite key to use in a dictionary.Įxample: We would come across a composite key if we need to create a telephone directory that maps, first-name, last-name, pairs of telephone numbers, etc. I want the same for loop to work if I pass in a list of size four. So it goes into the else block and prints “b is bigger.” Using tuples as keys in dictionaries Is it possible to simulate extended tuple unpacking in Python 2 Specifically, I have a for loop: for a, b, c in mylist: which works fine when mylist is a list of tuples of size three. 6>4, so the output a is biggerĬase 3: Comparison starts with a first element of each tuple. In this case 5>1, so the output a is biggerĬase 2: Comparison starts with a first element of each tuple. It starts with comparing the first element from each of the tuplesĬase1: Comparison starts with a first element of each tuple.
If they do not compare to =, then it proceed to the second element and so on. The comparison starts with a first element of each tuple. (company, emp, profile) = x # tuple unpackingĪ comparison operator in Python can work with tuples. Then the variable first will be assigned ‘m’, the variable last will be assigned ‘a’, and the variable middle will just be an empty list since there are no other values to assign to it.X = ("Guru99", 20, "Education") # tuple packing If there are not enough values to unpack for the mandatory variables, we will get a ValueError.įor example, if we used the following assignment instead: first, *middle, last = ‘ma' The middle variable, due to using the * or unpacking operator, can have any number of values, including zero. This feature often seems simple after you’ve learned about it, but it can be tricky to recall multiple assignment when you need it most. Note: The first and last variables above are called mandatory variables, as they must be assigned concrete values. Multiple assignment (also known as tuple unpacking or iterable unpacking) allows you to assign multiple variables at the same time in one line of code. And the variable middle will contain all the letters between ‘M’ and ‘l’ in the form of a list. The last letter, ‘l’, is assigned to the variable last. As such, the first letter of ‘Michael’ is assigned to the variable first, which would be ‘M’ in this case.
The values on the right side of the assignment operator will be assigned to the variables on the left depending on their relative position in the iterable object. We can do so as follows: first, *middle, last = nameĪnd that’s it! Since name is a string, and strings are iterable objects, we can unpack them. Let’s say that we have a string assigned to the variable name: name = ‘Michael’Īnd we want to break this name up into 3 parts, with the first letter being assigned to a variable, the last letter being assigned to another variable, and everything in the middle assigned to a third variable.