You can do something like this as demonstrated in perlfaq4: sub uniq { my %seen; grep !$seen{$_}++, @_; } my @array = qw(one two three two three); my @filtered = uniq(@array); print “@filtered\n”; Outputs: one two three If you want to use a module, try the uniq function from List::MoreUtils
Perhaps table is what you are after? dummyData = rep(c(1,2, 2, 2), 25) table(dummyData) # dummyData # 1 2 # 25 75 ## or another presentation of the same data as.data.frame(table(dummyData)) # dummyData Freq # 1 1 25 # 2 2 75
pd.unique returns the unique values from an input array, or DataFrame column or index. The input to this function needs to be one-dimensional, so multiple columns will need to be combined. The simplest way is to select the columns you want and then view the values in a flattened NumPy array. The whole operation looks … Read more
In addition, use collections.Counter to refactor your code: from collections import Counter words = [‘a’, ‘b’, ‘c’, ‘a’] Counter(words).keys() # equals to list(set(words)) Counter(words).values() # counts the elements’ frequency Output: [‘a’, ‘c’, ‘b’] [2, 1, 1]
sorted(iterable): Return a new sorted list from the items in iterable. CODE import pandas as pd df = pd.DataFrame({‘A’:[1,1,3,2,6,2,8]}) a = df[‘A’].unique() print(sorted(a)) OUTPUT [1, 2, 3, 6, 8]
I had some doubts about this basic but important issue, so I decided to learn by example. Let’s create test table master with two columns, con_id with unique constraint and ind_id indexed by unique index. create table master ( con_id integer unique, ind_id integer ); create unique index master_unique_idx on master (ind_id); Table “public.master” Column … Read more
As of NumPy 1.13, one can simply choose the axis for selection of unique values in any N-dim array. To get unique rows, one can do: unique_rows = np.unique(original_array, axis=0)
You might want to look at the uniq and sort applications. ./yourscript.ksh | sort | uniq (FYI, yes, the sort is necessary in this command line, uniq only strips duplicate lines that are immediately after each other) EDIT: Contrary to what has been posted by Aaron Digulla in relation to uniq‘s commandline options: Given the … Read more
CREATE TABLE someTable ( id serial PRIMARY KEY, col1 int NOT NULL, col2 int NOT NULL, UNIQUE (col1, col2) ) autoincrement is not postgresql. You want a integer primary key generated always as identity (or serial if you use PG 9 or lower. serial was soft-deprecated in PG 10). If col1 and col2 make a … Read more
If you just need sampling without replacement: >>> import random >>> random.sample(range(1, 100), 3) [77, 52, 45] random.sample takes a population and a sample size k and returns k random members of the population. If you have to control for the case where k is larger than len(population), you need to be prepared to catch … Read more