itertools.groupby(iterable) clear solution for Compress List by David_Jones - python coding challenges

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itertools.groupby(iterable) solution in Clear category for Compress List by David_Jones

from itertools import groupby

def compress(items):
    for k,_ in groupby(items):
        yield k

Jan. 30, 2020

Comments:

Striga on Dec. 2, 2020, 2:47 p.m.
I like it!

tvylormvde on Feb. 10, 2021, 12:34 p.m.
nice!

penedesimio on April 3, 2021, 8:51 p.m.
Very clean solution! I like the use of yield.

penedesimio on April 3, 2021, 8:56 p.m.
Very clean solution! I like the use of yield.

dubi95 on July 29, 2021, 5:46 p.m.
It seems so easy now, great!

dernovoyaleksey on June 14, 2022, 3:50 p.m.
Nice solution! But I don't understand why the 'yield' function was used?

oduvan on June 20, 2022, 3:24 p.m.
<a href="https://anandology.com/python-practice-book/iterators.html">any type of iterator</a> is acceptable as a solution for that function

Pactp on March 21, 2023, 8:41 a.m.
Nice solution. It is short, but readable and clear.

mlahor on Nov. 20, 2023, 9:48 p.m.
ChatGPT-generated explanation: The provided Python function compress takes an iterable items as input and yields a compressed version of this iterable, where consecutive duplicates are reduced to a single instance of each element. To understand how this function works, let's break it down: from itertools import groupby: The function groupby from the itertools module must be imported to use this function. groupby is a function that groups consecutive elements in an iterable that have the same value (or the same value when a key function is applied). def compress(items): This line defines a function named compress that takes one argument items, which is expected to be an iterable (like a list, tuple, etc.). for k, _ in groupby(items): Inside the function, a for loop iterates over the result of groupby(items). The groupby function returns an iterator that produces tuples of the form (key, group), where key is the value of the items being grouped, and group is an iterator of all items in the group. In this loop, k is used to capture the key, and _ (a common convention for an unused variable) captures the group. Since the group is not needed in this function, it's ignored with _. yield k: For each group, the function yields the key k. This means that for each set of consecutive duplicates in items, only one of those duplicates (the first one encountered) is yielded. This effectively compresses the sequence by removing consecutive duplicates. Here's an example to illustrate how compress works: Input: [1, 1, 2, 3, 3, 3, 4, 1, 1] Output from compress: [1, 2, 3, 4, 1] In this example, consecutive duplicates like 1, 1 at the start are compressed to a single 1, and the three consecutive 3s are compressed to a single 3. However, notice that the 1 at the end is still included because it's not directly consecutive to the first 1 (there are other numbers in between).

U.V on Jan. 22, 2025, 9:52 a.m.
Fine example of using .groupby !

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