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Python Python Collections (2016, retired 2019) Tuples Combo

Posted by Mathew Yangang
Mathew Yangang
4,433 Points

return list of tuple

I'm trying to return a list of tuple , but can't figure out how

combo.py 
# combo([1, 2, 3], 'abc')
# Output:
# [(1, 'a'), (2, 'b'), (3, 'c')]
def combo([1,2,3],'boy'):
    a = [1,2,3]
    b = 'boy'
    for num_string in a,b:
        return a,b.append(list(tuple))

2 Answers

Mustafa Başaran
Mustafa Başaran
28,046 Points
Mustafa Başaran
Mustafa Başaran
28,046 Points

Hi Matthew,

You do not need to assign values to variables within the function. You only need to set them as parameters to your function such as a, b. In other words, they are placeholders and will be assigned values when you make use of the function after you define it. 

def combo(a, b):
    # create an empty list so that you can return it as output at the end of the function.
    output = []
    # iterate over the iterable with a range(len()) construction. a and b have the same length by assumption 
    # this loop will give you all the index values starting from 0 to len(a) - 1  
    for i in range(len(a)):
        # get the items from a and b with index position i and assign them to a tuple, tup 
        tup = (a[i], b[i])
        # append tup to the list, output
        output.append(tup)
    # the loop is finished. return the list, output
    return output
Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

It looks like you have a few other issues going on there as well. Here's some hints:

  • the function parameters should just be names, they may represent lists or strings
  • you will used the passed-in data by referencing those names, no literal data items
  • you can initialize an empty list before the loop
  • in the loop, you can add to your list but not return it yet
  • creating a tuple can be done by just surrounding two items separated by a comma in parentheses
  • return the new list after the loop finishes
Mathew Yangang
Mathew Yangang
4,433 Points

Thanks Steven, but i don't understand step 2 on passed in data by referencing the names. Can you please elaborate a little bit on that?

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

The first 2 go together, so for example:

def combo(a, b):  # so if the parameters are named "a" and "b"
#    a = [1,2,3]    then you would not assign fixed values to them
#    b = 'boy'