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import random 
liste = [random.randint(1, 5) for i in range(random.randint(2, 15))]]
a,*b,c = liste[0], liste[1:len(liste) - 1], liste[len(liste) - 1]

When i run the code above I do not get the result I would have liked. For b for example I would like b to be [4, 5, 2, 2, 3, 1, 4, 5, 4, 5, 3], but I get [[4, 5, 2, 2, 3, 1, 4, 5, 4, 5, 3]]. Why do I have a list in a list and how do I fix it?

Basically I would like to know what I should write instead of liste[1:len(liste) - 1]. Also in my requirements I have to use *b.

If you're using Python 3.5+, you can instead use:

a, *b, c = liste

so that a and c would be the first and the last item in the liste list, and b would be the sublist in between, which is what your code apparently intends to do.

Python args and kwargs: Demystified – Real Python, In this step-by-step tutorial, you'll learn how to use args and kwargs in a closer look at the single and double-asterisk unpacking operators,  First, extract the author's arguments: Any author worth reading will have a point or thesis to their writing. The first thing to do is figure out the thesis (or theses, as the case may be.)

Use b instead of *b. Then b will be a list of values instead of list containing list of values.

import random
liste = [random.randint(1, 5) for i in range(random.randint(2, 15))]
a, b, c = liste[0], liste[1:len(liste)-1], liste[len(liste)-1]
print(a, b, c, sep='\n')

Output:

3
[2, 1, 1, 1, 2, 3, 2, 1, 3, 1]
5

How to extract parameters from a list and pass them to a function call , You can unpack a tuple or a list into positional arguments using a star. def add(a, b, c): print(a, b, c) x = (1, 2, 3) add(*x). Similarly, you can use  In other words, *args means zero or more arguments which are stored in a tuple named args. When you define function without *args, it has a fixed number of inputs which means it cannot accept more (or less) arguments than you defined in the function. In the example code below, we are creating a very basic function which adds two numbers.

Given an iterable, a star on the left will absorb all the elements that didn't fit into the initial and final portions of the assignment list, into a list.

So you have a couple of options here. The first is to get rid of the star. You're trying to assign three input elements to the output elements:

a, b, c = liste[0], liste[1:-1], liste[-1]

Notice how I shortened those indices and suddenly everything became legible.

Your second option is to expand the right side too:

a, *b, c = listed

This only works if you're trying to chop off exactly one element from the front and back though.

Finally, you can always just write things out explicitly instead of creating temporary lists along the way:

a = random.randint(1, 5)
b = [random.randint(1, 5) for _ in range(random.randint(0, 13)]
c = random.randint(1, 5)

Packing and Unpacking Arguments in Python?, To pass these packed arguments to another method, we need to do unpacking - def __init__(self, *args, **kwargs): #some code here  In Python, the single-asterisk form of *args can be used as a parameter to send a non-keyworded variable-length argument list to functions. It is worth noting that the asterisk ( *) is the important element here, as the word args is the established conventional idiom, though it is not enforced by the language.

Python Function Unpacking ( *args and **kwargs ), provide the correct amount of arguments needed (after unpacking); following an arbitrary argument, you can only pass named arguments; arbitrary arguments will​  Once we have this ‘packed’ variable, we can do things with it that we would with a normal tuple. args[0] and args[1] would give you the first and second argument, respectively. Since our tuples are immutable, you can convert the args tuple to a list so you can also modify, delete and re-arrange items in i.

How to use *args and **kwargs in Python, ) is used to pass a non-keyworded, variable-length argument list, and the double asterisk form is used to pass a keyworded, variable-length argument list. *args and **kwargs are mostly used in function definitions. *args and **kwargs allow you to pass a variable number of arguments to a function. What does variable mean here is that you do not know before hand that how many arguments can be passed to your function by the user so in this case you use these two keywords. *args is used to send a non

pack and unpack, as a second argument, and returns a list of individual values extracted from the string. Home Example how to use Args on x++. Example how to use Args on x++. December 26, 2014 May 8, 2015 Sti F. Cavendish AX 2012, Calling Menu item with Args X++;

Comments
  • Can you fix the formatting of your code so we can copy and paste it and have it actually run?
  • Invalid syntax still. Voting to close.
  • Don't use the *b. Use b.
  • In my requirements I have to use *b
  • Thank you for your help but I have the answer that I wanted which is a, *b, c = liste