![]() One should keep in mind that this kind of code will seldom be more readable or practical than having a full function. So, if one uses a trick to execute multiple expressions inside a lambda - I usually do that by creating a tuple and just returning the last component of it, it is possible to do the following: > a = lambda p:(x:=p, y:=p, x ** 2 + y ** 2) Since the release of Python 3.8, PEP 572 - assignment expressions - have been available as a tool. The way to go would be to raise this issue on the Python ideas mailing list, but be prepared to argue a lot over there to gain some traction.Īctually, just not to say "there is no way out", a third way could be to implement one more level of lambda calling just to unfold the parameters - but that would be at once more inefficient and harder to read than your two suggestions: min(points, key=lambda p: (lambda x,y: (x*x + y*y))(*p)) Do join my email list to get notified whenever I publish.No, there is no other way. I write coding articles (once per 1–2 days) that would have probably helped the younger me speed up my learning curve. Hopefully, this was useful and easy to understand. If we try to do something like this, we simply get an error: a, b, *others, *others2 = lis # error Some Final Words ![]() Note that we can only have 1 * operator per assignment. Tuple Unpacking With * Operator - A Couple More Examples lis = Įxample 1: a, b, *others = lis # a = 1, b = 2 # others = Įxample 2: *others, a, b = lis # a = 7, b = 8 # others = Įxample 3: a, b, *others, c, d = lis # a = 1, b = 2 # c = 7, d = 8 # others = Notice that name is assigned to "bob", age is assigned to 25, gender is assigned to "male", and others is assigned to a list containing everything else. We can use the * operator together with tuple unpacking to achieve this: name, age, gender, *others = lis print(name) # bob print(age) # 25 print(gender) # male print(others) # Let’s say we only care about the name, age, and gender. This can be a handful to write, especially if not all of these values are relevant. If we were to unpack this stuff normally, we might need to do this: name, age, gender, occupation, race, religion, tax_id = lis Let’s say we have a list containing the name, age, gender, occupation, race, religion, and tax id of a certain person: lis = Note that if you do this, make sure that the number of variables is equal to the length of the list, or else we might get an error Tuple Unpacking With * Operator - When There Are Too Many Things To Unpack We can use tuple unpacking to unpack these 3 values into 3 variables too: name, age, breed = lis Let’s say we have a list containing the name, age, and breed of a dog. We too can do this using tuple unpacking: lis, lis = lis, lis Unpacking Stuff From Existing List Let’s say we want to switch the first and second elements, in order to make lis =. We can extend this functionality to switch stuff inside a list: lis = ![]() We can achieve this using tuple unpacking too: a, b = b, a Switching Variables Inside A List Let’s say we wish to switch the variables a and b such that a=5 and b=4. Tuple Unpacking To Switch Variables a = 4 b = 5 When using tuple unpacking, make sure the number of variables on the left-hand side matches the number of values on the right-hand side. Same thing if we assign 2 variables to 3 values: a, b = 4, 5, 6 # ValueError: too many values to unpack (expected 2) In this example, we assign 3 variables a, b & c to 2 values 4 and 5. print(a) # prints 1 print(b) # prints 2 print(c) # prints 3 print(d) # prints 4 print(e) # prints 5 Tuple Unpacking - Wrong Number Of Variables a, b, c = 4, 5 # ValueError: not enough values to unpack (expected 3, got 2) The first variable a is assigned to the first value 1, the second variable b is assigned to the second value 2, and so on. Here, we have 5 variables on the left side, and 5 values on the right side. Let’s say we have more variables: a, b, c, d, e = 1, 2, 3, 4, 5 We can do this in one line using tuple unpacking, like this: a, b = 4, 5Ī will be 4, and b will be 5 - this does the exact same thing as the previous chunk of code. Let’s say we want to assign variables a and b to integers 4 and 5. Using this concept known as tuple unpacking, we can assign multiple things in just one line of Python. x = 1 y = "hello" print(x) # this prints 1 print(y) # this prints hello x=1 assigns the variable x to an integer value of 1, y="hello" assigns the variable y to a string value of "hello". If you’re a beginner at Python, you probably know about the assignment operator.
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