How can I extract all first value in a column from other column?

Question

I got a table like this:

house
house
house
dog
dog
dog

And I would like to have only first occurrence of each different words. So I would like to have a column like this:

house     house
house
house
dog       dog
dog
dog

Yes I tried a loop to get every first elements but it still not works — Pierre, Apr 12 '22 at 14:12
duplicate : https://stackoverflow.com/questions/7961363/removing-duplicates-in-lists — Ren, Apr 12 '22 at 14:21

Sadcow · Accepted Answer · 2022-04-12T14:22:45.967

2

If it is a dataframe, you can use:

df.column_name.unique()

if it is a numpy array:

np.unique(array)

If it is a list:

unique = list(set(data))

If you don't have the full data and it depends on anything else, you can use a function like:

   # initialize a null list
   unique_list = []
 
    # traverse for all elements
   for x in data: # read the data 
         # check if exists in unique_list or not
       if x not in unique_list:
           unique_list.append(x)

edited Apr 12 '22 at 14:22

answered Apr 12 '22 at 14:10

Sadcow

680
5
13

thanks ! but it is not data frame :/ – Pierre Apr 12 '22 at 14:11
What is the type of your data? – Sadcow Apr 12 '22 at 14:12
I just try to do it with a loop if it is possible, because in my software, I can't use function you gave me – Pierre Apr 12 '22 at 14:13
I've just updated the answer for list and array. However, the type of your data and question is not clear yet. – Sadcow Apr 12 '22 at 14:15
I just tried to do a code with loop, like for i in 1:N, if ... – Pierre Apr 12 '22 at 14:16

How can I extract all first value in a column from other column?

1 Answers1