Is there a way to get one value from a tuple in Python using expressions?
def tup():
return (3, "hello")
i = 5 + tup() # I want to add just the three
I know I can do this:
(j, _) = tup()
i = 5 + j
But that would add a few dozen lines to my function, doubling its length.
You can write
i = 5 + tup()[0]
Tuples can be indexed just like lists.
The main difference between tuples and lists is that tuples are immutable - you can't set the elements of a tuple to different values, or add or remove elements like you can from a list. But other than that, in most situations, they work pretty much the same.
For anyone in the future looking for an answer, I would like to give a much clearer answer to the question.
# for making a tuple
my_tuple = (89, 32)
my_tuple_with_more_values = (1, 2, 3, 4, 5, 6)
# to concatenate tuples
another_tuple = my_tuple + my_tuple_with_more_values
print(another_tuple)
# (89, 32, 1, 2, 3, 4, 5, 6)
# getting a value from a tuple is similar to a list
first_val = my_tuple[0]
second_val = my_tuple[1]
# if you have a function called my_tuple_fun that returns a tuple,
# you might want to do this
my_tuple_fun()[0]
my_tuple_fun()[1]
# or this
v1, v2 = my_tuple_fun()
Hope this clears things up further for those that need it.
Single elements of a tuple a can be accessed -in an indexed array-like fashion-
via a[0], a[1], ... depending on the number of elements in the tuple.
If your tuple is a=(3,"a")
a[0] yields 3,a[1] yields "a"def tup():
return (3, "hello")
tup() returns a 2-tuple.
In order to "solve"
i = 5 + tup() # I want to add just the three
you select the 3 by:
tup()[0] # first element
so all together:
i = 5 + tup()[0]
Go with namedtuple that allows you to access tuple elements by name (and by index). Details are at https://docs.python.org/3/library/collections.html#collections.namedtuple
>>> import collections
>>> MyTuple=collections.namedtuple("MyTuple", "mynumber, mystring")
>>> m = MyTuple(3, "hello")
>>> m[0]
3
>>> m.mynumber
3
>>> m[1]
'hello'
>>> m.mystring
'hello'
_is also just a variable. It's just often used to assign value to it that can be discarded. But theoretically you can get the value from_