Meaning of list[-1] in Python - Stack Overflow
I have a piece of code here that is supposed to return the least common element in a list of elements, ordered by commonality: def getSingle(arr): from collections import Counter c = Counte...
What is the difference between list [1] and list [1:] in Python?
2012年10月5日 · By using a : colon in the list index, you are asking for a slice, which is always another list. In Python you can assign values to both an individual item in a list, and to a slice of the list.
Python: list of lists - Stack Overflow
The first, [:], is creating a slice (normally often used for getting just part of a list), which happens to contain the entire list, and thus is effectively a copy of the list. The second, list(), is using the actual …
What is the difference between list and list [:] in python?
2010年11月2日 · When reading, list is a reference to the original list, and list[:] shallow-copies the list. When assigning, list (re)binds the name and list[:] slice-assigns, replacing what was previously in the …
slice - How slicing in Python works - Stack Overflow
The first way works for a list or a string; the second way only works for a list, because slice assignment isn't allowed for strings. Other than that I think the only difference is speed: it looks like it's a little …
Difference between List, List<?>, List<T>, List<E>, and List<Object>
The notation List<?> means "a list of something (but I'm not saying what)". Since the code in test works for any kind of object in the list, this works as a formal method parameter. Using a type parameter …
java - List<Object> and List<?> - Stack Overflow
2016年4月15日 · You cannot do this because List is an interface and you cannot create object of any interface or in other word you cannot instantiate any interface. Moreover, you can assign any object …
python - Access item in a list of lists - Stack Overflow
2014年7月19日 · You can access the elements in a list-of-lists by first specifying which list you're interested in and then specifying which element of that list you want. For example, 17 is element 2 in …
java - Create a List of primitive int? - Stack Overflow
2013年8月2日 · List<Integer> might lead to devastating memory fragmentation. Java maintains constant pool for some integers in 0..128 range but generally Java allocates a new object for each 32-bit …
How do I make a flat list out of a list of lists? - Stack Overflow
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 …