Posts

Showing posts with the label python list

Featured Post

SQL Interview Success: Unlocking the Top 5 Frequently Asked Queries

Image
 Here are the five top commonly asked SQL queries in the interviews. These you can expect in Data Analyst, or, Data Engineer interviews. Top SQL Queries for Interviews 01. Joins The commonly asked question pertains to providing two tables, determining the number of rows that will return on various join types, and the resultant. Table1 -------- id ---- 1 1 2 3 Table2 -------- id ---- 1 3 1 NULL Output ------- Inner join --------------- 5 rows will return The result will be: =============== 1  1 1   1 1   1 1    1 3    3 02. Substring and Concat Here, we need to write an SQL query to make the upper case of the first letter and the small case of the remaining letter. Table1 ------ ename ===== raJu venKat kRIshna Solution: ========== SELECT CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS capitalized_name FROM Table1; 03. Case statement SQL Query ========= SELECT Code1, Code2,      CASE         WHEN Code1 = 'A' AND Code2 = 'AA' THEN "A" | "A

Here's Python Program for List Duplicates

Image
Here is a program to find the item that occurs most frequently in a data structure. So why to find frequent item? Maybe it is the most purchased item on your shopping site. Perhaps it is the web page that gets hit the most often. If you are a tester, it could easily be the test that has had the most failures over the last year. Whatever it is, you want an easy way to find the data you need, and Python is here to help you. Python List duplicates Here are the two simple lists: list_1 = [1,2,3,2,3,2]  list_2 = ['a', 'b', 'a', 'b', 'c'] We can't do simple math on the individual items  since the second list contains characters. For example, it could contain the words of a book, and you want to find the most commonly used word in the work.  Also, it maybe list of UPC values for commonly purchased items. Whatever it is, all we can guarantee is that the data is probably comparable, in that we can compare one of the items to another. Yet we need to f

These Tips Helpful to Remove Python List and Dictionary Duplicates

Image
In this post, I have shared top ideas to remove duplicates from the list. Those are with Append and Dictionary. 1. How to Remove Duplicates with Append # Here is a list with duplicates list_with_duplicates = [1,2,3,12,1,2,3,4,5,6,1,2,3,7,8,9] It is simple if you follow the first-approach - brute force approach: list_without_duplicates = [] for pd in list_with_duplicates:   if pd not in list_without_duplicates:       list_without_duplicates.append(pd) print(list_without_duplicates) Result: [1, 2, 3, 12, 4, 5, 6, 7, 8, 9] This method has performance issues when the list is bigger in size.  Real-time. 2. How to Remove Duplicates with Dictionary # Here is you can convert a list to a dictionary dict_without_duplicates = dict(zip(list_with_duplicates, list_with_duplicates)) print(dictionary_without_duplicates) Result: {1: 1, 2: 2, 3: 3, 12: 12, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9} Real-time. Once again, this works and has the advantage of taking less space than duplicating the entire list.