405 How do I concatenate two lists in Python? As of 3.9, these are the most popular stdlib methods for concatenating two (or more) lists in Python. ... * A solution will qualify as a generalized solution if it …

Apr 4, 2009 · Closed 9 years ago. Is the a short syntax for joining a list of lists into a single list ( or iterator) in python? For example I have a list as follows and I want to iterate over a,b and c.

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 …

Nov 11, 2009 · Explanation Everything in Python is an object, including lists. All objects have a header of some sort in the C implementation. Lists and other similar builtin objects with a "size" in Python, in …

Sep 4, 2010 · I want to filter strings in a list based on a regular expression. Is there something better than [x for x in list if r.match(x)] ?

Caveats Linear time-complexity in list length An index call checks every element of the list in order, until it finds a match. If the list is long, and if there is no guarantee that the value will be near the …

First, I strongly recommend that you rename your variable list to something else. list is the name of the built-in list constructor, and you're hiding its normal function. I will rename list to a in the following. …

Apr 30, 2013 · 29 Since Python 3.5 (PEP 448 -- Additional Unpacking Generalizations) one can use the following literal syntax to convert a tuple to a list:

What is a good way to find the index of an element in a list in Python? Note that the list may not be sorted. Is there a way to specify what comparison operator to use?

465 This question already has answers here: How do I add together integers in a list (sum a list of numbers) in python? (5 answers) How can I iterate over overlapping (current, next) pairs of values …