How do you remove duplicate values in array in Python?-CodePudding

I have an array where each element is the mean of a set of random numbers. I want to be able to remove duplicate values in this array. How would I go about doing this?

So far I have tried:

for i in range(len(array)):
    
    for j in array:

        if array[i] == j:

and then some operation to remove the element from the array. However, this will just remove every instance of every duplicated element.

CodePudding user response：

You can try to create the array of a set:

deduplicated_array = list(set(array))

CodePudding user response：

If you don't care about the order of the elements then use the following

deduplicated = list(set(array))

CodePudding user response：

You could simply use np.unique():

unique_values = np.unique(array)

CodePudding user response：

You may want to look into using a python set :)

Example with code:

# set cannot have duplicates
# Output: {1, 2, 3, 4}
my_set = {1, 2, 3, 4, 3, 2}
print(my_set)

# we can make set from a list: what you want
# Output: {1, 2, 3}
my_set = set([1, 2, 3, 2])
print(my_set)

Then you can use remove or discard (if you don't want errors upon removing non-existing items):

my_set = {1, 3, 4, 5, 6}
print(my_set)

# discard an element
# Output: {1, 3, 5, 6}
my_set.discard(4)
print(my_set)

# remove an element
# Output: {1, 3, 5}
my_set.remove(6)
print(my_set)

# discard an element
# not present in my_set
# Output: {1, 3, 5}
my_set.discard(2)
print(my_set)

# remove an element
# not present in my_set
# you will get an error.
# Output: KeyError

my_set.remove(2)

If you prefer to work with a list, then you can then convert back to a list with the list function:

my_list = list(my_set)

Docs: https://python-reference.readthedocs.io/en/latest/docs/sets/