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pythoniteratortuplespython-itertoolscycle

Itertool Cycle function to access the first value only once in tuple

I want to add the first value in a tuple to a list which is something like this t=((1,2,3,4), (5,6,7,8))

I want to use cycle function (some question) to access the first value of tuple i.e. t[0] to store in a list i.e equivalent to this:

list1=[]
list1.append(t[0])

How can I use cycle (if one has to) to cycle through the tuple t to store the first indexed value in list1?

Solution

  • Slurp all elements from an iterable

    You can use extend:

    t=((1,2,3,4), (5,6,7,8))
lst = []

lst.extend(t[0])  # takes an iterable
print(lst)

    Output:

    [1, 2, 3, 4]

    Append an element from every indexed tuple

    If you wanted to append only the first index of every entry in the tuple t:

    t=((1,2,3,4), (5,6,7,8))
lst = [_t[0] for _t in t]
print(lst)

    Output:

    [1, 5]