What are the reserved keywords in Python

What are python reserved keywords?

When coding in the Python language there are particular python reserved words that the system uses, which cannot be accessed as a variable or a function as the computer program uses them to perform specific tasks.

When you try to use them, the system will block it and throws out an error. Running the below code in Python

import keyword
keywordlist = keyword.kwlist
print(keywordlist)

Produces the below keyword values
['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del',
'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal',
'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']

When writing your code, it is important to follow the following guidelines:

(A) Research the keywords first for the language you are writing in.

(B) Ensure that your programming language highlights keywords when used, so you can fix the issue.

(C) Setup your computer program in debug mode to highlight keywords use.

With some programs running into thousands of lines of code, with additional functions and variables, it can become harder to spot the problem, so good rigour in the initial stages of coding will help down the road any issues that you may find that need to fixed.

This code was run in Python version 3.8

Python tutorial: Create an input box in Tkinter

Using an tkinter input box for your data projects

There may be an occasion as you are building out a data science or data analytics project, checks need to be performed on the dataset as follows:

  •  Big data sets and speed requirements in conjunction with
  • The need to reduce the volume of data returned which is impeding performance

and this is where input boxes and Tkinter can help!

In the below video, we are demonstrating an introduction to using an input box and validating the input.

We demonstrate how to validate the data entered into the tkinter input box and return a message, this will ensure the user gets the correct data.

Types of uses for a tkinter input box are varied, here are some thoughts:

  • Use an input box to return a set of data for a particular day.
  • Using them to filter down the results to a particular cohort of data.
  • Conduct a string search to find data quality issues to be fixed.

Python tutorial: How to create a graphical user interface in tkinter

How would you like to present your data analytics work better?

When starting your data analytics projects, one of the critical considerations is how to present your results quickly and understandably?

Undoubtedly this is true if you are only going to look at the results yourself.

If the work you do is a repeatable process, a more robust longer-term solution needs to be applied, this is where Tkinter can help, which is a python graphical user interface.

There are many applications for using Tkinter, such as:

  • Use them to build calculators.
  • They can show graphs and bar charts.
  • Show graphics on a screen.
  • Validate user input.

Where this all fits in with data analytics?

While going through a set of data and getting some meaning to it can be challenging, using the python graphical user interface tutorial below can help build the screens that will allow a repeatable process to display in a meaningful way.

Ultimately, you could do the following:

  • Build a screen that shows data analytics errors in a data set, e.g. The number of blank column values in a dataset.
  • Another application is to run your analytics to show the results on a screen that can be printed or exported.
  • Similarly, you could also have a screen where a user selects several parameters that are fed into the data analytics code and produces information for the user to analyse.

There are many more ways that you could do this, but one of the most important things is that data analytics can be built into a windows environment using Tkinter that the user would be used to seeing. As a result, this could help to distribute a solution across an enterprise to lots of different users.

The only thing that needs to happen is that the requirements the user needs are defined, and the developer then builds on those, with the data analytics code run in the background of this program with Tkinter and output into a user-friendly screen for review.

 

How to create a combobox in tkinter

Here we have delivered a complimentary video to How to create a graphical user interface in Tkinter, demonstrating how a Combobox can be used to select values and then validate the entry chosen.

Using a Combobox in the computer programming world has been in use for some time. It is a useful way to select from a choice and could in many ways in data analytics help as the following examples show:

  • Select a date to filter a data set down to values that are in the dataset at that point.
  • Using matplotlib to plot data points in charts, you could have dynamic values that change the diagram based on values chosen from the Combobox.
  • Utilising data analytics reports that the user accesses, the Combobox could be used to change the data shown dynamically to allow comparisons.
  • When looking to fix data quality issues, use the Combobox to select values for a date that needs to be fixed, apply the fixes on screen and then save back to the database.

Developing a Tkinter GUI and the possibilities it brings

In this video, we use ttk, written to help split the behaviour of code from the code implementing its appearance; you can see plenty more on it here ttk information. You will find this a handy piece of functionality so that styling an object will not interfere with how it works.

We also have a function that helps with the validation as follows:

def checkifireland ():
    x = combolist.get() # asssigns the value inside the combobox to x so it can be processed
    if x == "Ireland":
        messagebox.showinfo("Correct answer", "You will love it in Ireland")
    else:
        messagebox.showinfo("Incorrect answer", "You should visit Ireland first!")

The effectiveness is especially handy as it helps to ensure that the code returned from the Combobox to the function is correct, as the below video will show.

The next steps

There are many informative Python – working with excel videos which are on our YouTube channel.

We are looking to bring them in and show on a graphical user interface tutorial.

If you subscribe to the channel, you will get to see those videos as they are uploaded.

tkinter python tutorial

Let’s make the introductions 🙂
Tkinter is a package that allows a programmer to build a GUI interface, which then can be opened on a computer screen by a user. There are many different types of GUI apps, but examples include a calculator or a text editor that opens when you click it.

Tkinter would be the most commonly used GUI package in Python, due to its simplicity, but PySimpleGUI, PYQt or PySide are other alternatives. Ensure you research these before using to make sure they suitable for your needs.

Why use Tkinter?

  • Relatively simple and easy to learn, upskilling is quick.
  • A great introduction to the concepts and ideas for building GUI apps, you will get a good grounding in the techniques and approaches needed.
  • Very well documented, so a programmer should be able to find the answer to anything specific they need to understand.

 

Now we are introduced, let’s see how to utilise it:

Install Python as usual, and make sure that tkinter is working and you have the correct version. Note that import tkinter is for version 3.x, before that use import Tkinter

When saving your python script DO NOT call it tkinter.py as I did, the import statement will not work. Call it something like tkinter_test.py, see red arrow below.

 

At the start of the video below the code will look like this:

Added to this code in the following video:

  • Button – which will open our YouTube channel
  • An image
  • A clickable link – Which will bring you to our Home Page

A screenshot of the final output is as follows:

See a link to the Python documentation here Tkinter on python.org

How to check if a file is empty

Ever wondered how to about checking if a file is empty?

A problem you may come across in Data Analytics that when you are importing a file as outlined in this post Python – How to import data from files is how do we know if the files are empty or not before import?

In the world of data, there are several reasons to check :

  • You have an automated process relying on the import not been empty.
  •  A process that preceded you receiving the file did not work.
  • The amount of time and effort to investigate the problem causes undue work to fix.

The nuts and bolts of it all

Here we have a video that looks at different scenarios on how to bring in files. The following functionality appears in this video:

  • os.path.getsize – This looks to get the file size attached to the file. * Please see note below
  • pd.read_csv
  • pd.read_excel

The add on bits

*One note about os.path.getsize, which we found:

  • It only works in the logic provided if the size of the file is zero KB.
  •  CSV and XLSX files even though they where created empty, when saved had a file size greater than zero.
  •  TXT files, when created empty and saved, had a file size of zero.

 

Hope this video helps explain further how empty files can be checked in python before they are processed.

Thanks!

Data Analytics Ireland