I have a dataframe containing a single column of IDs and all other columns are numerical values for which I want to compute z-scores. Here’s a subsection of it: Some of my columns contain NaN values which I do not want to include into the z-score calculations so I intend to use a solution offered to this question: how to
Tag: indexing
Easiest way to include a stop parameter in enumerate python?
Ss there a simple way to iterate over an iterable object that allows the specification of an end point, say -1, as well as the start point in enumerate. e.g. So if my object has a length of 10, what is the simplest way to to get it to start iterating at index 2 and stop iterating at index 9?
Index all *except* one item in python
Is there a simple way to index all elements of a list (or array, or whatever) except for a particular index? E.g., mylist[3] will return the item in position 3 milist[~3] will return the whole list except for 3 Answer For a list, you could use a list comp. For example, to make b a copy of a without the
Access multiple elements of list knowing their index [duplicate]
This question already has answers here: Explicitly select items from a list or tuple (9 answers) Closed 7 months ago. I need to choose some elements from the given list, knowing their index. Let say I would like to create a new list, which contains element with index 1, 2, 5, from given list [-2, 1, 5, 3, 8, 5,
How to get the index with the key in a dictionary?
I have the key of a python dictionary and I want to get the corresponding index in the dictionary. Suppose I have the following dictionary, Is there a combination of python functions so that I can get the index value of 1, given the key value ‘b’? I know it can be achieved with a loop or lambda (with a
Indexing with boolean arrays into multidimensional arrays using numpy
I am new to using numpy and one thing that I really don’t understand is indexing arrays. In the tentative tutorial there is this example: I have no idea why it does that last thing. Can anyone explain that to me? Thanks! Answer Your array consists of: One way of indexing it would be using a list of integers, specifying
Python: return the index of the first element of a list which makes a passed function true
The list.index(x) function returns the index in the list of the first item whose value is x. Is there a function, list_func_index(), similar to the index() function that has a function, f(), as a parameter. The function, f() is run on every element, e, of the list until f(e) returns True. Then list_func_index() returns the index of e. Codewise: Is
Get the index of an element in a queryset
I have a QuerySet, let’s call it qs, which is ordered by some attribute which is irrelevant to this problem. Then I have an object, let’s call it obj. Now I’d like to know at what index obj has in qs, as efficiently as possible. I know that I could use .index() from Python or possibly loop through qs comparing
How do I get the last element of a list?
How do I get the last element of a list? Which way is preferred? Answer some_list[-1] is the shortest and most Pythonic. In fact, you can do much more with this syntax. The some_list[-n] syntax gets the nth-to-last element. So some_list[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down to some_list[-len(some_list)], which gives