Given a list of lists t, which means: is faster than the shortcuts posted so far. (t is the list to flatten.) Here is the corresponding function: As evidence, you can use the timeit module in the standard library: Explanation: the shortcuts based on + (including the implied use in sum) are, of necessity, O(T**2) when there are T sublists — as the intermediate … Read more
Using an additional state variable, such as an index variable (which you would normally use in languages such as C or PHP), is considered non-pythonic. The better option is to use the built-in function enumerate(), available in both Python 2 and 3:
Reference: Data Structures > More on Lists Caveats follow Note that while this is perhaps the cleanest way to answer the question as asked, index is a rather weak component of the list API, and I can’t remember the last time I used it in anger. It’s been pointed out to me in the comments that because this answer is heavily … Read more
First, let’s see what this does:Arrays.asList(ia) It takes an array ia and creates a wrapper that implements List<Integer>, which makes the original array available as a list. Nothing is copied and all, only a single wrapper object is created. Operations on the list wrapper are propagated to the original array. This means that if you shuffle the list … Read more
Reference: Data Structures > More on Lists Caveats follow Note that while this is perhaps the cleanest way to answer the question as asked, index is a rather weak component of the list API, and I can’t remember the last time I used it in anger. It’s been pointed out to me in the comments that because this answer is heavily … Read more
Use an Iterator and call remove():
As indicated by the other answers, the error is to due to k = list[0:j], where your key is converted to a list. One thing you could try is reworking your code to take advantage of the split function: Note that if you are using Python 3.x, you’ll have to make a minor adjustment to … Read more
The effects of the three different methods to remove an element from a list: remove removes the first matching value, not a specific index: del removes the item at a specific index: and pop removes the item at a specific index and returns it. Their error modes are different too:
The len() function can be used with several different types in Python – both built-in types and library types. For example:
This question already has answers here: How to concatenate items in a list to a single string? How can I convert a list to a string using Python?