Python Articles - Page 723 of 1048

Suppose we have an array of numbers and have another number k, we have to check whether given array can be divided into pairs such that the sum of every pair is k or not.So, if the input is like arr = [1, 2, 3, 4, 5, 6], k = 7, then the output will be True as we can take pairs like (2, 5), (1, 6) and (3, 4).To solve this, we will follow these steps −n := size of arrif n is odd, thenreturn Falselow := 0, high := n - 1while low < high, doif arr[low] + ... Read More

Suppose we have a Queue with first n natural numbers (unsorted). We have to check whether the given Queue elements can be sorted in non-decreasing sequence in another Queue by using a stack. We can use following operations to solve this problem −Push or pop elements from stackDelete element from given Queue.Insert element in the other Queue.So, if the input is like Que = [6, 1, 2, 3, 4, 5], then the output will be True as we can pop 6 from Que, then push it into stack. Now pop all remaining elements from Que to another queue, then pop ... Read More

Suppose we have two coordinates on a chessboard for queen and opponent. These points are Q and O respectively. We have to check whether the queen can attack the opponent or not. As we know that the queen can attack in the same row, same column and diagonally.So, if the input is like Q = (1, 1) O = (4, 4), then the output will be True as Q can go (4, 4) diagonally.To solve this, we will follow these steps −if x of Q is same as x of O, thenreturn Trueif y of Q is same as y ... Read More

Suppose we have a prime number n. we have to check whether we can express n as x + y where x and y are also two prime numbers.So, if the input is like n = 19, then the output will be True as we can express it like 19 = 17 + 2To solve this, we will follow these steps −Define a function isPrime() . This will take numberif number

Suppose we have a rectangle represented by two points bottom-left and top-right corner points. We have to check whether a given point (x, y) is present inside this rectangle or not.So, if the input is like bottom_left = (1, 1), top_right = (8, 5), point = (5, 4), then the output will be TrueTo solve this, we will follow these steps −Define a function solve() . This will take bl, tr, pif x of p > x of bl and x of p < x of tr and y of p > y of bl and y of p < ... Read More

Kivy is an pen source Python library for rapid development of applications that make use of innovative user interfaces, such as multi-touch apps. It is used to develop the Android application, as well as Desktops applications. In this article we will see how to add labels to the windows created through Kivy.Creating LabelIn the below example we create a window and give it a custom label by using Label function available in uix.lable module. Once we run the app with this code we get the new window showing the custom label.Examplefrom kivy.app import App from kivy.uix.label import Label class ... Read More

In data analysis using python we may come across situation when two lists need to be merged. But it may be a challenge to handle the duplicate elements present in those lists. In this article we will see how to combine two lists by maintain all the elements form the first list and only the unique elements from the second list.Using extendIn this approach we take the first list and create a result list. Then we design a for loop to check for the presence of element of the first list in the second list and if the element is ... Read More

A list in python is normally a 1D list where the elements are listed one after another. But in a 2D list we have list nested inside the outer list. In this article we will see how to create a 2D list from a given 1D list. We also supply the values for the number of elements inside the 2D list to the program.Using append and indexIn this approach we will create a for loop to loop through each element in the 2D list and use it as an index for the new list to be created. We keep incrementing ... Read More

Given a nested list we want to convert it to a dictionary whose elements can be considered as part of a tree data structure. In this article we will see the two approaches to convert a nested list into to add dictionary whose elements represent a tree like data structure.Using SlicingWe reverse the items in the list aby slicing and then check if the item is present in the list. If it is not present we ignore it else we add it to the tree.Exampledef CreateTree(lst):    new_tree = {}    for list_item in lst:       currTree = ... Read More

Python dictionaries have keys and values. If we have two or more dictionaries to be merged a nested dictionary, then we can take the below approaches. Here year the dictionaries are given along with the new keys that will become a key in the nested dictionary.Assigning keysIn this approach we will create a new empty dictionary. Then assigned the given dictionaries to each new key. The resulting dictionary will be a nested dictionary with the keys assigned.ExampledictA = {'Sun': 1, 'Mon': 2} dictB = {'Tue': 3, 'Sun': 5} # Given Dictionaries print("DictA : ", dictA) print("DictB: ", dictB) ... Read More