Hướng dẫn count array python
How can I count the number of elements in an array, because contrary to logic array.count(string) does not count all the elements in the array, it just searches for the number of occurrences of string. asked Oct 9, 2008 at 14:12
UnkwnTechUnkwnTech 85k65 gold badges183 silver badges227 bronze badges 2 The method len() returns the number of elements in the list. Syntax:
Eg:
Output:
answered Oct 9, 2008 at 14:14
2
Functions encased with double underscores are usually "special methods" implementing one of the standard interfaces in Python (container, number, etc). Special methods are used via syntactic sugar (object creation, container indexing and slicing, attribute access, built-in functions, etc.). Using answered Oct 9, 2008 at 19:40
Jeremy BrownJeremy Brown 17.2k3 gold badges33 silver badges27 bronze badges 1 If you have a multi-dimensional array, len() might not give you the value you are looking for. For instance:
This code block will return true, telling you the size of the array is 2. However, there are in fact 10 elements in this 2D array. In the case of multi-dimensional arrays, len() gives you the length of the first dimension of the array i.e.
To get the number of elements in a multi-dimensional array of arbitrary shape:
answered Aug 11, 2015 at 9:03
user2993689user2993689 2433 silver badges11 bronze badges 3 Or,
if you want to be oopy; "len(myArray)" is a lot easier to type! :) answered Oct 9, 2008 at 14:23
Kevin LittleKevin Little 12.1k5 gold badges38 silver badges47 bronze badges 4 Before I saw this, I thought to myself, "I need to make a way to do this!"
And then I thought, "There must be a simpler way to do this." and I was right.
answered Jul 17, 2015 at 3:05
Hàm count() trong Python trả về số lần xuất hiện của chuỗi con trong khoảng [start, end]. Đếm xem chuỗi str này xuất hiện bao nhiêu lần trong chuỗi string hoặc chuỗi con của string nếu bạn cung cấp chỉ mục ban đầu start và chỉ mục kết thúc end. Các tham số:
str1 = "vi du ham count trong Python, hoc lap trinh Python" sub = "Py" print ("str1.count(sub, 4, 40) : ", str1.count(sub, 10, 60)) sub = "ham"; print ("str1.count(sub) : ", str1.count(sub)) Kết quả là: Output: str1.count(sub, 4, 40) : 2 str1.count(sub) : 1 |