Data Analytics Ireland

What is Javascript?

admin — Sat, 01 Apr 2023 18:46:40 +0000

JavaScript is a high-level, interpreted programming language that is widely used in web development. It was created by Brendan Eich at Netscape in 1995 and has since become one of the most popular programming languages in the world. What is JavaScript used in conjunction with? JavaScript is often used in conjunction with HTML and CSS...

What is Jupyter notebook?

admin — Sat, 01 Apr 2023 18:25:28 +0000

Jupyter Notebook is an open-source web-based interactive computing environment that allows users to create and share documents that contain live code, equations, visualizations, and narrative text. What languages does it support? It supports many programming languages, including Python, R, and Julia, and is widely used in scientific computing, data analysis, and machine learning. What does...

Read More “What is Jupyter notebook?” »

What is Assembly Language?

admin — Fri, 31 Mar 2023 21:01:06 +0000

Assembly language is a low-level programming language that is used to write programs for specific computer hardware, such as microcontrollers or embedded systems. It is considered a “low-level” language because it is more closely related to the computer’s hardware architecture than higher-level programming languages like Python, Java, or C++. What is assembler code? Assembly language...

What is an Algorithm?

admin — Fri, 31 Mar 2023 20:47:56 +0000

An algorithm is a set of instructions or rules designed to solve a specific problem or complete a specific task. It is a step-by-step procedure for performing a calculation, data processing, or automated reasoning. Algorithms can be implemented in a variety of forms, including as computer programs, mathematical formulas, or flowcharts. Where are algorithms used?...

Read More “What is an Algorithm?” »

What is Visual Studio Code?

admin — Fri, 31 Mar 2023 20:11:58 +0000

“Visual Studio Code” (VS Code) is a free and open-source code editor developed by Microsoft. What Operating systems is it available for? It is available for Windows, Linux, and macOS. What features does it offer? VS Code offers a range of features including syntax highlighting, code completion, debugging, source control integration, and an extensible plugin...

What are anonymous functions in Julia?

admin — Thu, 30 Mar 2023 22:25:05 +0000

In Julia, anonymous functions are functions that are defined without being assigned a name. They are sometimes also called lambda functions or function literals. An anonymous function is created using the syntax args -> expr, where args is a comma-separated list of arguments and expr is the expression that defines the body of the function....

What does the … operator do in Julia?

admin — Tue, 28 Mar 2023 22:20:48 +0000

In Julia, the ... operator, also known as the “splat” or “ellipsis” operator, is used to unpack the contents of a collection or tuple. Here are a few common use cases: In the example below, we create our Tuple and then call it in the function which then prints it out. 2. Function definitions: The...

What are bitwise operators in Julia?

admin — Sat, 25 Mar 2023 13:22:09 +0000

In Julia, bitwise operators are used to manipulate the binary representation of integers. They operate on the individual bits of a number and perform logical operations such as AND, OR, XOR, and NOT. What is bitwise? Bitwise refers to the manipulation of binary digits (bits) at the level of individual bits. Bitwise operations involve comparing,...

What are Local and Global Variables in Python?

admin — Sat, 18 Mar 2023 22:30:39 +0000

In Python, a variable’s scope determines where the variable can be accessed from within a program. The two main scopes for variables are local and global. What are Local Variables? Local variables are defined within a function and can only be accessed within that function. They are not accessible outside the function. Once the function...

What is Julia used for?

admin — Sat, 18 Mar 2023 21:26:11 +0000

Julia is a high-level, high-performance programming language that is designed for numerical and scientific computing, data analysis, and machine learning. Julia is used for a wide range of tasks, including: Scientific computing Julia is particularly well-suited for scientific computing tasks, including simulations, modeling, and analysis of large data sets. Machine learning Julia provides powerful libraries...

Read More “What is Julia used for?” »

What are the built-in exceptions in Julia?

admin — Thu, 16 Mar 2023 23:49:52 +0000

As of the time of writing this blog list, below are a list of built-in exception-handling errors. Julia has a number of built-in exception types that are used to indicate errors and handle exceptional conditions during program execution. Some of the most common built-in exception types in Julia include: Exception ArgumentError BoundsError CompositeException DimensionMismatch DivideError...

How can packages be managed in Julia?

admin — Thu, 16 Mar 2023 23:24:26 +0000

The packages in Julia can be managed using a built-in package manager called Pkg. The Pkg package provides a set of commands that allow users to install, update, and remove packages, as well as manage their dependencies. How to use the Pkg package manager To use the Pkg package manager, you simply open a Julia...

Why choose Julia over other programming languages?

admin — Thu, 16 Mar 2023 23:07:33 +0000

There are several features that make it a better choice over other programming languages, especially for scientific and technical computing. Performance Julia is designed to be a high-performance language, with a speed that is comparable to that of C or Fortran. Its just-in-time (JIT) compilation allows for fast execution times, while its type system and...

What is The Julia Programming Language

admin — Thu, 16 Mar 2023 22:32:59 +0000

Julia is a high-level, high-performance programming language designed for numerical and scientific computing, data science, and machine learning. Why was it developed? It was developed with the goal of providing a fast, dynamic, and easy-to-use language for high-performance computing, while also being accessible to non-expert programmers. When was Julia released? Julia was first released in...

What is Data Integrity?

admin — Mon, 27 Feb 2023 21:18:27 +0000

Data integrity refers to the accuracy and consistency of data stored in a database or other data storage system. It ensures that the data in the system is reliable, accurate, and consistent over time. How is data integrity maintained? Data integrity is maintained by enforcing data validation rules, referential integrity constraints, and other data integrity...

Read More “What is Data Integrity?” »

Explain different types of data Normalization.

admin — Mon, 27 Feb 2023 20:56:23 +0000

Normalization is a process of organizing data in a database to reduce data redundancy and ensure data integrity. There are several types of normalization, each with its own set of rules for eliminating data redundancy and improving data integrity. The most commonly used normalization levels are: There are also higher levels of normalization, such as...

What is the difference between DROP and TRUNCATE in SQL?

admin — Mon, 27 Feb 2023 20:22:50 +0000

DROP and TRUNCATE are two SQL commands that can be used to remove data from a table, but they work in different ways: How to drop a table from a database It is important to remember that if you have the same name spread over a few databases, you should reference the correct databases, to...

What is Denormalization of data in a database?

admin — Thu, 23 Feb 2023 20:31:30 +0000

Denormalization is the process of adding redundant data to a database to improve query performance. It involves intentionally violating the normal forms of database design in order to simplify or speed up queries by reducing the number of joins or eliminating the need for certain indexes. The normal forms of database design are a set...

What is Query Optimization in SQL?

admin — Thu, 23 Feb 2023 20:20:28 +0000

Query optimization in SQL refers to the process of improving the performance of SQL queries by selecting the most efficient execution plan for the query. When a SQL query is executed, the database management system (DBMS) must determine the best way to retrieve the requested data from the database. Query optimization involves analyzing the query...

What is a Clustered Index in SQL?

admin — Thu, 23 Feb 2023 20:09:48 +0000

In SQL, a clustered index is a type of index that determines the physical order of the data in a table. It organizes the table data based on the values in one or more columns, and stores the data in the table accordingly. When a clustered index is created on a table, the rows of...

What is a Unique key in SQL?

admin — Thu, 23 Feb 2023 20:00:17 +0000

In SQL, a unique key is a constraint that ensures that the values in a column or set of columns are unique across all rows in a table and that the values cannot be null. A unique key is similar to a primary key, but it differs in that it does not necessarily need to...

What Are Constraints in SQL?

admin — Thu, 23 Feb 2023 19:46:12 +0000

In SQL, constraints are rules that are enforced on a table’s data to maintain the integrity and accuracy of the data. Constraints can be applied to one or more columns in a table, and they can be added or removed as needed. Here are some of the most common types of constraints in SQL: Constraints...

What is the difference between CHAR and VARCHAR2 in SQL?

admin — Thu, 23 Feb 2023 19:31:34 +0000

In SQL, both CHAR and VARCHAR2 are character data types, but they have some differences in terms of their storage and usage. CHAR: VARCHAR2: Here’s an example to illustrate the difference: In the char_test table, the name and address columns are both defined as CHAR, with fixed lengths of 10 and 20 characters, respectively. If...

What is the difference between SQL and MySQL?

admin — Thu, 23 Feb 2023 19:16:11 +0000

SQL(Structured Query Language) and MySQL are related but distinct concepts. SQL is a programming language that is used to manage relational databases, while MySQL is a specific relational database management system (RDBMS) that uses SQL as its query language. Here are some key differences between SQL and MySQL: In summary, SQL is a language used...

How many python functions are there?

admin — Thu, 23 Feb 2023 19:04:04 +0000

The exact number of Python functions is not fixed as it can change with new versions of Python and the addition of new modules and packages. Python is an open-source language with a large standard library and an active community of developers who are constantly adding new features and functions. The Python Standard Library alone...

What is a CTE in SQL?

admin — Thu, 23 Feb 2023 18:44:51 +0000

CTE stands for Common Table Expression, and it is a temporary named result set that you can reference within a SQL statement. A CTE is defined within a query and is available only for the duration of that query. It allows you to create a named temporary table that you can reference multiple times within...

Read More “What is a CTE in SQL?” »

What are Lambda functions in Python?

admin — Sun, 19 Feb 2023 16:21:00 +0000

Lambda functions are anonymous functions that take any amount of arguments as their input, but can only have one expression. Let’s look at the function further Lambda functions are anonymous and are usually classified as user-defined functions but without a name. One thing that makes Lambda functions different from regular functions is that they do...

TypeError: expected str, bytes or os.PathLike object, not DataFrame

admin — Sat, 18 Feb 2023 17:17:55 +0000

If you are working with files and trying to open them to read in their contents, sometimes errors will pop in that may not immediately be obvious how to resolve. In this blog post, we discuss a TypeError that is associated with opening a file in Python and reading in its contents. So how may...

TypeError: not all arguments converted during string formatting

admin — Sat, 18 Feb 2023 16:16:15 +0000

In our latest post, we are going to discuss formatting issues that you may come across. It relates to how you format the data when passing it from the input of a user. This scenario can happen as a result of user input, which then has some comparisons completed on it. How does the problem...

How to use zip() function in Python

admin — Wed, 15 Feb 2023 17:33:13 +0000

Sometimes you need a function that will help you to aggregate or combine severable iterables in one go. When we read the official Python documentation it states that using zip ” Iterates over several iterables in parallel, producing tuples with an item from each one.” So what does that actually mean? Well in essence essentially...

How to pass by reference or pass by value in Python

admin — Sun, 12 Feb 2023 14:05:41 +0000

To start off passing by reference basically means that you are telling the program you have written to pass a variable to a function. When passing arguments to a function, it is important to understand the meanings first. As a result, when you pass by reference to a function, the variable data gets processed and...

What is Apache Spark and what is it used for?

admin — Sun, 12 Feb 2023 11:14:19 +0000

You have been probably looking at large sets of data for a while, and projects to extract insights from them. If you are given a set of data that is so large you may need something more! This is where Apache Spark comes in! So what does Apache Spark do? It performs the following functions:...

How Would You Change The Name Of a Key in a Python Dictionary

admin — Tue, 03 Jan 2023 22:13:42 +0000

In our last example of working with dictionaries, we showed you How To Delete a Set of Keys From a Python Dictionary. This is a very useful scenario if you want to tidy up the dictionary and remove data not required. Following on from that, in this post, we are going to look at changing...

How To Delete a Set of Keys From a Python Dictionary

admin — Tue, 03 Jan 2023 21:38:37 +0000

In our last video on how to delete a key from a python dictionary, we illustrated where one key could be removed easily. But what if you wanted to remove one or more keys? In the below code, we have created an empty dictionary. This will be populated by values in “dictionary_remove”. Option1 uses the...

How to delete a key from a Python dictionary

admin — Wed, 09 Nov 2022 21:11:21 +0000

This is an addition to the list of questions you may get when in an interview and you are asked to give an overview of Python. As with how to create an empty dictionary in Python, how to add values to a python dictionary, and how to sort a python dictionary we will take you...

How to sort a Python Dictionary

admin — Wed, 09 Nov 2022 20:42:49 +0000

In our Python Overview Interview Questions we started off the process of trying to prepare you how to answer any questions that may come up in an interview scenario. We then moved on to show how to discuss Python Dictionary Interview Questions and what may come up. One of the questions that you may be...

How To Add Values to a Python Dictionary

admin — Sat, 22 Oct 2022 17:03:17 +0000

As part of our ongoing series about Python Interview questions, we discussed how you would create an empty dictionary. In this posting, we are going to go through the different ways you could add values to your dictionary. In the below code, we have created an empty dictionary for you. So as we go down...

How To Create An Empty Dictionary In Python

admin — Sat, 22 Oct 2022 16:30:54 +0000

In our recent video Python dictionary interview questions, we discussed a number of topics around Python dictionaries . Here we will discuss how to create an empty dictionary. In the below code, you will see there are two ways to create: Creating empty dictionaries has many benefits as you can manipulate them as they are...

Python Dictionary Interview Questions

admin — Wed, 19 Oct 2022 18:38:36 +0000

In our first video on python interview questions we discussed some of the high-level questions you may be asked in an interview. In this post, we will discuss interview questions about python dictionaries. So what are Python dictionaries and their properties? First of all, they are mutable, meaning they can be changed, please read on...

Python Overview Interview Questions

admin — Sun, 02 Oct 2022 20:50:41 +0000

So you have landed an interview and worked hard at upskilling your Python knowledge. There are going to be some questions about Python and the different aspects of it that you will need to be able to talk about that are not all coding! Here we discuss some of the key elements that you should...

ValueError: Columns must be same length as key

admin — Wed, 21 Sep 2022 21:56:50 +0000

Are you looking to learn python, and in the process coming across this error and trying to understand why it occurs? In essence, this usually occurs when you have more than one data frames and in the process of writing your program you are trying to use the data frames and their data, but there...

Create a HTML Table From Python Using Javascript

admin — Wed, 24 Aug 2022 22:05:14 +0000

So you are using Python and you have data stored in a data frame? You would like to present that on a webpage HTML table, but unsure how to achieve this. Well, read on to see two different methods that will help you. Pass the data to Javascript which then passes to the HTML the...

How To Check For Unwanted Characters Using Loops With Python

admin — Sun, 21 Aug 2022 09:00:47 +0000

On this website, we have posted about how to remove unwanted characters from your data and How to remove characters from an imported CSV file both will show you different approaches. In this blog posting, we are going to approach the process by using loops within a function. Essentially we are going to pass a...

How to Create Multiple XML Files From Excel With Python

admin — Mon, 01 Aug 2022 14:16:18 +0000

So you have an Excel file that has hundreds or maybe thousands of records, but you want to convert it to an XML file, and have each row as a separate file? This can be achieved very easily using Python, in three easy steps. First of all, what is XML? XML stands for “extensible markup...

How To Fix TypeError: unhashable type ‘slice’

admin — Tue, 26 Jul 2022 21:20:50 +0000

So you have a Python dictionary, and you want to retrieve data from it and print it to a screen. There are some characteristics of Python that first of all should be understood: The last point is very important as dictionaries do not have an index value, and this is why you get the TypeError...

TypeError: Array() Argument 1 Must Be A Unicode Character, Not List

admin — Sat, 11 Jun 2022 20:01:48 +0000

In a recent post, we discussed arrays and what they mean, and how they differ from lists. When you have a list in an array, one of the things that you need to define is what data type it is. If you don’t then the array will throw the error that you are on this...

How To Run Python Validation From Javascript

admin — Mon, 02 May 2022 20:52:23 +0000

More and more, website developers are looking to blend different programming technologies to allow them to use functionality, that maybe is not available to them in the current programming language they utilise. In previous posts how to pass python variables to Javascript and how to run python directly from javascript, we touched on how to...

How to Pass Python Variables to Javascript

admin — Mon, 28 Mar 2022 22:13:48 +0000

In our recent blog posting How to Pass a Javascript Variable to Python using JSON, we demonstrated how to easily use AJAX to pass whatever data you wanted and then manipulate it with Python. In this blog posting, we are going to show how to do this the other way around. The scenario is that...

How to pass multiple lists to a function and compare

admin — Fri, 18 Feb 2022 21:31:39 +0000

Have you ever been faced with a situation where you have multiple lists you want to compare, and need a function that will read them in and show you what is different between them all? In this scenario, this can be handy where you have large data sets and need a quick way to find...

How to run Python directly from Javascript

admin — Mon, 14 Feb 2022 00:01:45 +0000

Are you developing a website and looking to execute some Python script directly from the website? Here we take you through how to achieve this using Python Flask, the scenarios we demonstrate are as follows: In both scenarios above you will be presented with pop-up boxes like below, but the python code can be changed...

What Is An Array In Python?

admin — Tue, 18 Jan 2022 22:25:57 +0000

Python arrays are used to manage how data is analyzed and have the data in a structured form for the data analyst or data scientist to use. What is an Array? An array has the following properties: What are the differences between arrays and lists? For the most part arrays and lists are the same,...

How to show percentage differences between files in Python

admin — Sun, 16 Jan 2022 12:28:19 +0000

In our previous post on how to compare CSV files for differences we showed how you could see the differences, but what if you wanted to see if a record was 100% matched or not? Here we are going to use SequenceMatcher which is a python class that allows you to compare files and return...

How to Pass a Javascript Variable to Python using JSON

admin — Mon, 13 Dec 2021 20:43:23 +0000

So you have an application or website that is capturing data using javascript, and you want to pass this to Python, so you can process it further. Here using Flask, Python’s package for web development, we will show you how to achieve this, and also explain the JSON output. Where could this be useful? (A)...

How to use parameters in Python

admin — Fri, 19 Nov 2021 22:56:03 +0000

Are you using a function and looking to pass values into it to be processed? Well if this is the case you are trying to pass arguments to that function’s parameters so they will return a value for you. Parameters are just values that are associated with the function. For each function, you are going...

How to Generate Random Integers Between 0 and 9

admin — Wed, 17 Nov 2021 23:38:26 +0000

You may have a number of machine learning projects where you need a way to generate random integers to test your model assumptions. There are plenty of ways to achieve this, here we will take you through a number of different steps. To demonstrate this we take you through a number of different scenarios, but...

How to Automate Testing With Python | unittest

admin — Mon, 01 Nov 2021 00:13:00 +0000

So you are working with large amounts of data, and the data is having transformations applied to it or quite simply you need to see as you move data, has it changed in any way. The question that arises is if I have lots of validations to complete, how can I quickly see if they...

ValueError: cannot convert float NaN to integer

admin — Sat, 16 Oct 2021 09:45:03 +0000

Sometimes in your data analytics project, you will be working with float data types and integers, but the value NaN may also appear, which will give you headaches if you don’t know how to fix the problem at hand. A NaN is defined as “Not a Number” and represents missing values in the data. If...

TypeError: List Indices Must Be Integers Or Slices, Not Tuple

admin — Sat, 09 Oct 2021 14:48:44 +0000

When working with Python lists in your data analytics projects, when you trying to read the data, a common problem occurs if you have a list of lists, and it is not properly formatted. In this instance, Python will not be able to read one or more lists and as a result, will throw this...

How to Create an XML file from Excel using Python

admin — Mon, 04 Oct 2021 21:13:59 +0000

Are you working on a data analytics project where you need to feed your data to a location that is able to process an XML file? The ability to get your data into a structured format like XML has many benefits: (A) You can transfer the data to a web service for processing. (B) Multiple...

How to Add Formulas to Excel using Python

admin — Mon, 06 Sep 2021 20:21:11 +0000

You may be working on automating some exports to Excel using Python to compare files or just pure and simple adding formulas to an Excel file before you open it up. Here we explain adding formulas to your Excel output using Numpy or adding the calculations to specific cells in the output. Adding formulas to...

How To Compare CSV Files for Differences

admin — Sat, 07 Aug 2021 15:07:25 +0000

Often a lot of data analytics projects involve comparisons, some of it could be to look at data quality problems, other times it could be to check that data you are loading has been saved to the database with no errors. As a result of this, there is a need to quickly check all your...

TypeError: the first argument must be callable

admin — Sat, 24 Jul 2021 14:13:57 +0000

So you may be using Python Classes and have encountered the problem TypeError: First Argument Must be Callable. So what does the problem mean and how can you fix it? In this article, we are looking to explain how it may occur and the easy fix you can apply to stop the problem in the...

TypeError: ‘NoneType’ object is not iterable

admin — Mon, 19 Jul 2021 19:25:25 +0000

Have you wondered why you cant iterate over a NoneType but never had it properly explained? Read on as here we will fully explain the concept and how you can fix it. So what is a NoneType anyway? First of all, to understand a none type, you need to understand what none is. None is...

How to create a calculated field in Tableau

admin — Sun, 27 Jun 2021 11:24:26 +0000

You are working on a data visualisation project, but in some instances the data may not be in a format that you want in the output. This is is where a calculated field comes in, it allows you define the output in a way you would like to see it. So what are calculated fields...

How to group your data in Tableau

admin — Sun, 27 Jun 2021 09:14:32 +0000

Have you learnt how to connect to your data in Tableau and now want to understand how to group your Tableau data? Here we go through a number of steps to help you understand better how to approach this, and what benefits it will bring to your data analytics project. Why would I group in...

How to Compare Column Headers in CSV to a List in Python

admin — Thu, 27 May 2021 19:43:21 +0000

So you have numerous different automation projects in Python. In order to ensure a clean and smooth straight-through processing, checks need to be made to ensure what was received is in the right format. Most but not all files used in an automated process will be in the CSV format. It is important there that...

How can I filter my data in Tableau?

admin — Tue, 25 May 2021 23:04:48 +0000

Tableau has some very powerful ways to manage your data through dimensions and measures. Once you are happy how your data is structured, you will then need to filter your data. Here we talk you through the process and how you can use it to your advantage. So why would I want to apply a...

What are measures in Tableau?

admin — Tue, 25 May 2021 22:04:49 +0000

Previously we discussed what are dimensions in Tableau. While they are important to understand, another vital part of Tableau data is measures, and they are equally important. So how does Tableau define measures? In their post on Tableau Measures, they define it as follows: Measures contain numeric, quantitative values that you can measure. Measures can be...

What are dimensions in Tableau?

admin — Fri, 14 May 2021 10:46:10 +0000

In our previous post, we showed you how to connect to your data in Tableau. Now that you are in we are going to discuss dimensions and what they can be used for. What are Dimensions? When you login to Tableau, you will see the dimensions information on the left hand side as below. We...

How to add a date when a record is created

admin — Thu, 13 May 2021 11:22:12 +0000

You maybe working with a lot of data and inserting it into tables, and want to create a date stamp so you can see when the record was created. Below we will take you through the steps of how to complete this in SQL server management studio. In this table we have created a new...

Import a CSV file with an SQL query

admin — Thu, 13 May 2021 10:43:32 +0000

In many of the SQL programming softwatre tools, there will most likely be an option for you to import your data torugh a screen they have provided. In SQL Server Management Studio the below screen is available to pick your file to import, and it quickly guides you through the steps. But what if you...

How to connect to your data in Tableau

admin — Mon, 10 May 2021 15:56:11 +0000

Right you have made the decision to utilise the benefits of data visualisation , to present your data in an easy to follow format. Tableau is one of the top industry tools that allows you to manage your data, and present it in a fashion that enables decision making. What are the ways to connect...

TypeError: ‘list’ object is not an iterator

admin — Sun, 09 May 2021 11:32:54 +0000

We have covered off many TypeErrors on this website, here we will go through which using a list with and it is not an iterator gives you errors. In order to understand this error better, we need to first understand what is an iterator in Python? An iterator is a Python object that has the...

How to count the no of rows and columns in a CSV file

admin — Tue, 04 May 2021 16:59:24 +0000

So you are working on a number of different data analytics projects, and as part of some of them, you are bringing data in from a CSV file. One area you may want to look at is How to Compare Column Headers in CSV to a List in Python, but that could be coupled with...

TypeError: ‘float’ object is not callable

admin — Tue, 04 May 2021 15:25:07 +0000

So you have been presented with the TypeError: ‘float’ object is not callable in Python, but unsure how to fix? Well read on so we can get you a solution. First things an overview of a Float A float is any number that can contain a decimal place separating an integer from the fractions to...

How to change the headers on a CSV file

admin — Mon, 03 May 2021 20:48:57 +0000

Problem statement You are working away on some data analytics projects and you receive files that have incorrect headings on them. The problem is without opening the file, how can you change the headers on the columns within it? To start off, lets look at file we want to change , below is a screen...

TypeError: ‘int’ object is not callable

admin — Mon, 03 May 2021 20:03:35 +0000

We have posted several python solutions to TypeErrors here on the website. Here is another one we hope you will find useful in solving a programming issue you may have. So what does the error mean? In the below code, we have four variables that have been assigned an integer. As can be seen we...

What is data profiling and its benefits?

admin — Fri, 30 Apr 2021 12:03:53 +0000

Data profiling is the process of creating statistics on a data set that will allow readers of the metrics to understand how good the data quality is for that data. Usually this is one of the many functions of a data analyst. Many organisations have data quality issues, and the ability to identify them and...

What is GITHUB, and should I use it?

admin — Sun, 18 Apr 2021 20:25:58 +0000

GITHUB was founded in April 2008 by Tom Preston-Werner, Chris Wanstrath, PJ Hyett and Scott Chacon. Its purpose is to host repositories, have version control, collaboration and bug tracking. The idea was to create a service that allowed the programming community to centrally track how they manage their code, allow collaboration on new ideas. Many open-source communities...

how to write subqueries in SQL

admin — Mon, 05 Apr 2021 15:20:16 +0000

In SQL a lot of the times there will be a need to write subqueries that will extract data that you can analyse. But what if you want to use the data as input to another query that can then be used to give you the result you desire? This is is the power of...

How to Group By in a Select Statement

admin — Mon, 05 Apr 2021 11:41:35 +0000

SQL group by is one of the most commonly used statements you will come across and it has many different applications. It is a great way to aggregate data, when you are using one of the following in the select statement: (A) Sum (B)Count (C) Average (D) Max (E) Min There are more that can...

IndexError: index 2 is out of bounds for axis 0 with size 2

admin — Sun, 04 Apr 2021 19:32:58 +0000

In Python you may come across IndexError: index 2 is out of bounds for axis 0 with size 2 from time to time. The error relates to the use of indexes and the no of columns you are referencing. We discussed single positional indexer is out-of-bounds and in that blog post, it was related to...

IndexError: single positional indexer is out-of-bounds

admin — Sun, 04 Apr 2021 12:04:11 +0000

Often you will get an error IndexError: single positional indexer is out-of-bounds that is referencing a row that does not exist based on its index value. When you want to look at a particular row in Python, there is a way that you can reference the row and then the values within it. Lets break...

IndexError: list index out of range

admin — Sun, 04 Apr 2021 10:08:22 +0000

Are you working with lists and getting the error IndexError: list index out of range while using Python? There is a very simple explanation to this, and its fix is very easy. First of all lets understand what is going on with the list. Lists and their index values In the below list, we have...

Free ways to Extract Data from Files

admin — Fri, 02 Apr 2021 15:19:47 +0000

Livestream #3 Are you on a limited budget but looking for free ways to extract data from files without using expensive online tools or companies that you will have to pay? Join us here for an overview of some tools and techniques that you most likely have access to already.

Deleting table records with SQL

admin — Sun, 21 Mar 2021 16:47:54 +0000

Often you will hear about deleting table records with SQL, but how is this achieved, if you have not done it before? In previous videos on SQL we discussed how to update records in SQL , how to insert data into a table in SQL. You could be faced with the scenario where there is...

how to update records in SQL

admin — Mon, 15 Mar 2021 14:03:17 +0000

There are multiple reasons for wanting to update records in a database table, from data quality to enriching your data for any machine learning projects. One example maybe where you want to add a creation date to a record. In this blog post we will look at how to update database records, and also where...

how to insert data into a table in SQL

admin — Tue, 09 Mar 2021 11:32:51 +0000

After building your data using a create statement, one of the next steps using SQL is to now get your data in, so it can be managed and updated where necessary. There are many ways to import your data including , one you could use is import a CSV file with an SQL query. Here...

ValueError: pattern contains no capture groups

admin — Sun, 07 Mar 2021 15:49:06 +0000

In Python, there are a number of re-occurring value errors that you will come across. In this particular error it is usually related to when you are running regular expressions as part of a pattern search. So how does the problem occur? In the below, the aim of the code is to purely create a...

What does a data analyst do?

admin — Sat, 06 Mar 2021 07:44:32 +0000

Livestream #2 – What does a data analyst do? You are probably sitting there hearing about big data and databases, data analytics and machine learning, and wondering where a data analyst fits in. Here we will look to break it down step by step. Difference between a Data Analyst and a Business Analyst Data Analyst...

Welcome to Data Analytics Ireland

admin — Sat, 27 Feb 2021 15:14:58 +0000

Livestream #1 Here is our first live stream, we discuss the channel, the areas of data analytics we cover, and the future direction and what the plans are for 2021.

How To Join Tables In SQL

admin — Sat, 20 Feb 2021 18:01:31 +0000

When running an sql select query, most likely we may have a need to bring in data from other tables. The reason for this is that tables have a specific purpose for the data they store. One of the most important features of a data architecture is to avoid duplication. This has the impact of...

Read More “How To Join Tables In SQL” »

TypeError: ‘str’ object is not callable

admin — Mon, 15 Feb 2021 22:47:21 +0000

This is a common TypeError that you will come across in Python, it is actually easy to diagnose how it occurred. To start off we need to understand “str” is a function in python, and it converts any value into a string. As a result, because it is a function your ability to call it...

TypeError: cannot unpack non-iterable int object

admin — Sun, 14 Feb 2021 22:02:52 +0000

Often when working on a data analytics project it requires you to split data out into its constituent parts. There are a number of reasons for this, it can be confusing when you get errors as with the title of this post. Before we explain this error and what it means, lets us first explain...

What is a Primary Key and Foreign Key

admin — Sun, 14 Feb 2021 20:12:44 +0000

When working with databases in your data analytics projects, most likely you will deal with more than one table. As a result in certain scenarios there will be a link between the tables This will ensure that you can use data from the two or more tables that can be joined together. But how would...

Tableau Desktop versus Tableau Server

admin — Thu, 11 Feb 2021 16:57:41 +0000

Are you working on a data analytics project, and seeking a way to present your data visually? Data Visualisation achieves this, and there are many products on the market place that you could use. In this blog post, we are going to discuss Tableau , one of the leading data visualisation tools in the market...

TypeError object of type ‘int’ has no len()

admin — Mon, 08 Feb 2021 21:35:35 +0000

I have seen this data type error come up numerous times while working on my data analytics projects, and recently decided to investigate further. On initial inspection, it can seem a bit of a funny one, but in actual fact, it is quite straight forward. Lets break it down and see what is going on...

how to create and drop a table in SQL

admin — Sat, 06 Feb 2021 17:20:32 +0000

If you are working on data analytics , and have access to databases that you can load data into and manipulate, then read on. There maybe a reason for you have your own partitioned table with data in it, but you need to know how to create a database. The creation of a table can...

how to use case statements in SQL

admin — Sat, 06 Feb 2021 13:55:58 +0000

In recent posts on SQL here on this website, we have covered off a number of ways to extract your data from wildcards to filters. Here we are going to build on that learning, but bring in a new dimension in the use of case statements. These are very handy to use when you may...

How to use wildcards in SQL

admin — Thu, 04 Feb 2021 16:03:14 +0000

Following on from from our previous posts on SQL, this post will help to explain how to use wildcards in your query. What would you use a wild card in the first place? When a data analyst dealing with a large dataset, it is most likely that they will not know every piece of data....