How to... Connect to Data in Files

One of the first steps you will take in any Data Preparation, Visualisation or analytics project is to Input Data. These inputs can come in many different forms but the most common still remains Files.

Files, upon files, upon files


For many, our first experiences of working with data probably involve one piece of ubiquitous software, Microsoft Excel. The spreadsheet has become the jack-of-all-trades for data storage, manipulation and basic reporting. Every organisation across the world has tens, if not hundreds of spreadsheets saved on every computer. All of these will contain useful information, raw data or reference tables that will help answer the questions experts are posing. 

The issues spreadsheets create

There are a number of potential issues this creates that whilst aren't unique to spreadsheets, they are considerations to make:
  • Accuracy - how has the data been changed since being added to the spreadsheet? 
  • Timeliness - how old is the data? 
  • Optimisation - any manipulation or analysis is often manual and non-repeatable
  • Size - with limits on rows and columns, sometimes the data grows beyond spreadsheets
  • Sharing - multiple people using multiple sheets can create confusion and errors
Organisations are complex. Merges, acquisitions and splits in organisations have created a complex history and network to unpick and the data often reflects this. Trying to ensure the data is what you think it is can be hard to prove and then maintain that clarity. 

It's not just Excel

Comma Separated Variables (CSV), Text, Spatial, Statistical files are all forms where data is likely to be living inside your computer that could help you answer the questions you have. All these file types are created and used for multiple reasons. Often they are default outputs from different programmes where you might be working with operational or analytical systems in your organisation. So what are these files and where do they come from:

CSV: can be output as a data storage file. Whether you are sharing data for programmes that are not in the Microsoft Suite or just simply moving data in to databases, CSVs are very flexible file types. Columns of data are separated by commas (hence the name) with new rows of data held on separate lines within the file. 

Text: are even more simplistic and therefore a smaller file to store. Again suited for holding data in a very simple format, text files have the potential to be more problematic to work with due to their ability to contain very different formats. 

Spatial: often created by Geographic Information Systems (GIS) tools, Spatial files can contain a lot of information to help spatial analysis. Spatial data files hold simple geographic objects like points, lines and polygons. These spatial objects can show a lot about data point relationships and patterns.  

Statistical: R and Python are becoming common tools to be taught in universities. Therefore, they are being demanded more in the workplace, especially by 'data scientists' and those working with statistics. Just because a model is created by a data scientist, doesn't mean the results are not required by experts in your organisation to complete further analysis. 

PDF: These files are becoming more common place and often contain useful datasets inside them. Depending on how the PDF has been formed and formatted makes a massive difference as to how easy these files are to be used and prepared.

Flexibility is not your friend

These file types can help hold a range of data and in lots of different formats. It's one of the many reasons they are used but creates a significant set of issues for us as Data Preppers. Each file will have its own structure, messiness and set of challenges that need to be overcome before the data can be used for analysis or augmented with other data sets to add extra value. 

Where to find your data files

They could be anywhere and everywhere. Knowing the right people in your organisation who may have collaborated with others or formed the files themselves is key. Here are a few considerations to make about where the files are held once you track them down:
On your computer formed by you
Building / forming your own data sets is a common task in the workplace. This might be from capturing numbers out of reports you read, records captured by you or aggregations of other data sets sent to you. 

On your computer formed by others
Emailed database extracts, survey results or market research are also common ways to receive data. The greatest challenge with this data is get the frequent updates you require to keep your analysis fresh. Getting information and insight in to data item definitions and 'freshness' of the data is easier as you are likely to know who to ask... now you just need to wait for them to reply. 

Cloud Storage
Team drives held on Cloud computers and servers create a new challenge as others will be adding files to shared drives. This makes tracking down the sources for the information a lot tougher. For example, such tasks as getting definitions of what data points mean, understanding what aggregations have been applied or knowing what data has been removed may be more difficult. Even the task of refreshing the dataset may be more challenging as the origins of the file(s) are difficult to trace.

So why bother?

The flexibility means so many useful bits of data will exist in these files. Whether it is projected budgets or targets through to the latest reorganisation structure to be applied to your earnings, you will need to be comfortable preparing these data sets for analysis. Now rather than using manual manipulation, you will be able to use Tableau Prep to be able to pick apart the useful from the dross and structure the data to be ready for your analysis. 

How to connect to these files in Prep

When opening Tableau Prep Builder you will find the 'Home' screen very similar to Tableau Desktop. To make any data connection, you will need to click on the '+' next to the word Connections.

This will expand the choice of connections you can make in Prep Builder to show all the connection types including the File Types listed above (except Spatial files as of version 2019.4).

By clicking on any of the file types, you will open a 'File Explorer' (Windows) or 'Finder' (Mac) to show the location of your file. Once you find the file, click open to make the connection to that file. Now it's time to prepare your data for your purposes.

Popular posts from this blog

2023: Week 1 The Data Source Bank

Image
 Created by: Carl Allchin Welcome to a New Year of Preppin' Data. These are weekly exercises to help you learn and develop data preparation skills. We publish the challenges on a Wednesday and share a solution the following Tuesday. You can take the challenges whenever you want and we love to see your solutions. With data preparation, there is never just one way to complete the tasks so sharing your solutions will help others learn too. Share on Twitter, LinkedIn, the Tableau Forums or wherever you want to too. Tag Jenny Martin, Tom Prowse or myself or just use the #PreppinData to share your solutions.  The challenges are designed for learning Tableau Prep but we have a broad community who complete the challenges in R, Python, SQL, DBT, EasyMorph and many other tools. We love seeing people learn new tools so feel free to use whatever tools you want to complete the challenges.  A New Year means we start afresh so January's challenges will be focused on beginners. We will use dif
Read more

2023: Week 2 - International Bank Account Numbers

Image
Challenge By: Jenny Martin For week 2 of our beginner month, Data Source Bank has a requirement to construct International Bank Account Numbers (IBANs), even for Transactions taking place in the UK. We have all the information in separate fields, we just need to put it altogether in the following order: Inputs A list of the transactions, with information about the receiving bank account  A lookup table for the SWIFT Bank Codes  Requirements Input the data In the Transactions table, there is a Sort Code field which contains dashes. We need to remove these so just have a 6 digit string ( hint ) Use the SWIFT Bank Code lookup table to bring in additional information about the SWIFT code and Check Digits of the receiving bank account ( hint ) Add a field for the Country Code ( hint ) Hint: all these transactions take place in the UK so the Country Code should be GB Create the IBAN as above ( hint ) Hint: watch out for trying to combine sting fields with numeric fields - check data types Re
Read more

How to...Handle Free Text

Image
Free isn't always a good thing. In data, Free text is the example to state when proving that statements correct. However, lots of benefit can be gained from understanding data that has been entered in Free Text fields. What do we mean by Free Text? Free Text is the string based data that comes from allowing people to type answers in to systems and forms. The resulting data is normally stored within one column, with one answer per cell. As Free Text means the answer could be anything, this is what you get - absolutely anything. From expletives to slang, the words you will find in the data may be a challenge to interpret but the text is the closest way to collect the voice of your customer / employee. The Free Text field is likely to contain long, rambling sentences that can simply be analysed. If you count these fields, you are likely to have one of each entry each. Therefore, simply counting the entries will not provide anything meaningful to your analysis. The value is in
Read more