CODEWITHSUNDEEP
pythonlistappend
Hannes
Hannes

Reputation: 21

Identical objects in list

is it possible to detect identical objects as different variables, say object1=(1,2,3) and object2=(1,2,3).

list = []

If i now put object 1 in the list together with object 2 the list becomes:

list.append(object1)
list.append(object1)
print(list)
list = [(1,2,3),(1,2,3)]

How can i let python decide whether or not the first element in the list is object1? This is something i have to do for my school project.

Upvotes: 1

Views: 550

Answers (3)

Hannes
Hannes

Reputation: 21

I found it. You can do this with the is function. 

Block1 is Block2
list[0] is list[1]

response: False

Upvotes: 0

kederrac
kederrac

Reputation: 17322

you could cast to set then back to list:

my_list = [(1,2,3),(1,2,3)]
print(list(set(my_list)))
# [(1, 2, 3)]

or you could check first if your object is already in the list:

if object1 not in my_list:
    my_list.append(object1)

Upvotes: 0

Quip13
Quip13

Reputation: 33

The computer does only what you tell it to do. So if you append something twice, it will listen. If you want it to do it under a condition, you need to use an if statement and compare the values within the list to the value you are trying to add. To make this easier, I would put this in a function so you can call this logic easily

In your case, I'm assuming you only want to add the object if it doesn't exist:

list = []
def addToList(elem):
    global list # allows the function to modify this variable that would be normally out of scope
    if elem not in list:
        list.append(elem)

object1 = [1,2,3]
addToList(object1)
addToList(object1)
print(list)

Upvotes: 1

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