Since a list comprehension creates a list, it shouldn't be used if creating a list is not the goal; it shouldn't be used simply to write a one-line for-loop; so refrain from writing [print(x) for x in range(5)] for example.

The second, list(), is using the actual list type constructor to create a new list which has contents equal to the first list. (I didn't use it in the first example because you were overwriting that name in your …

joined_list = [item for list_ in [list_one, list_two] for item in list_] It has all the advantages of the newest approach of using Additional Unpacking Generalizations - i.e. you can concatenate an arbitrary …

In Python 3, filter doesn't return a list, but a generator-like object. Finding the first occurrence If you only want the first thing that matches a condition (but you don't know what it is yet), it's fine to use a for …

Here's the timeit comparison of all the answers with list of 1000 elements on Python 3.9.1 and Python 2.7.16. Answers are listed in the order of performance for both the Python versions.

What really annoys me is that python says that when you don't set the start and the end, they default to 0 and the length of sequence. So, in theory, when you use "abcdef" [::-1] it should be transformed to …

Sep 17, 2012 · For handling a few strings in separate variables, see How do I append one string to another in Python?. For the opposite process - creating a list from a string - see How do I split a …

Don't use quotes on the command line 1 Don't use type=list, as it will return a list of lists This happens because under the hood argparse uses the value of type to coerce each individual given argument …

If your list of lists comes from a nested list comprehension, the problem can be solved more simply/directly by fixing the comprehension; please see How can I get a flat result from a list …

This means you can no longer use the predefined value of list, which is a class object representing Python list. Thus, when you tried to use the list class to create a new list from a range object: