It just uses the Python function array.index() and with a simple Try / Except, it returns the position of the record if it is found in the list and returns -1 if it is not found in the list (like in JavaScript with the …

Negative numbers mean that you count from the right instead of the left. So, list[-1] refers to the last element, list[-2] is the second-last, and so on.

In Python, you wouldn't use indexes for this at all, but just deal with the values— [value for value in a if value > 2]. Usually dealing with indexes means you're not doing something the best way.

1366 Using a for loop, how do I access the loop index, from 1 to 5 in this case? Use enumerate to get the index with the element as you iterate:

Aug 20, 2013 · I considered the case of a series with 25 elements and assumed the general case where the index could contain any values and you want the index value corresponding to the search value …

Nov 28, 2013 · An index, in your example, refers to a position within an ordered list. Python strings can be thought of as lists of characters; each character is given an index from zero (at the beginning) to …

Jul 8, 2009 · The way Python indexing works is that it starts at 0, so the first number of your list would be [0]. You would have to print [52], as the starting index is 0 and therefore line 53 is [52].

Feb 19, 2010 · For example in a string sentence, position of e is 1, 4, 7 (because indexing usually starts from zero). but what I find is both of the functions find() and index() returns first position of a character.

Oct 16, 2015 · Take the following data-frame: x = np.tile(np.arange(3),3) y = np.repeat(np.arange(3),3) df = pd.DataFrame({"x": x, "y": y}) x y 0 0 0 1 1 0 2 2 0 3 0 1 4 1 1 5 2 1 6 ...

137 Dictionaries are unordered in Python versions up to and including Python 3.6. If you do not care about the order of the entries and want to access the keys or values by index anyway, you can …