Python XIV

Mary PW Chin 钱碧慧博士
PhD (Wales), MSc (Surrey)
E-mail:

1st bite of Python

Printing

2nd bite of Python

Loops

3rd bite of Python

If-elif-else

4th bite of Python

Nested loops

5th bite of Python

Input, while, tables

6th bite of Python

Strings

7th bite of Python

Simple maths

8th bite of Python

More loops

9th bite of Python

Dictionaries

10th bite of Python

Drawing

11th bite of Python

Statistics & histograms

12th bite of Python

Pretty nets

13th bite of Python

Medical scans

14th bite of Python

Handwriting recognition

15th bite of Python

Flower recognition

Handwriting recognition

Slides here are continuously being revised and updated. If you have been here before, your browser might have some old files cached. To ensure that you see the latest version, please follow the instructions given in the following link: ☞ how to clear browser cache.

Gentle reminder

For every program you encounter it is always an excellent exercise to change the variable names to names which are most meaningful to you, then make the program run. You will gain deeper understanding of the program. You will see the program in a new light. Everyone is different: variable names most intuitive to me differ from variable names most intuitive to you. My programs are written with variable names most intuitive to me, so you should change them to names most intuitive to you so that the program flow becomes more obvious.

Project

Collect some samples of handwritten digits, digitise either by scanning with a scanner or just take a photo. If you choose to take a photo, try your best to keep the aspect ratio correct -- avoid photo-taking from an angle. Down-sample the images to 8 by 8 pixels using a graphics software. Without down-sampling, there would be no hope of getting this exercise to work. Transfer the image files to your file space (PythonAnywhere is you are using PythonAnywhere, or wherever you run Python). Use matplotlib.pyplot.imread to read the files. Modify the program given in the slides, run and see whether the program can recognise the digits in your samples.

You may also try typing out digits on your favourite word-processor, use the full collection of fonts available. Save as image files. Remember to downsample to 8 by 8 pixels per digit. Try using your newly collected samples as training dataset or testing dataset.

1st bite of Python

Printing

2nd bite of Python

Loops

3rd bite of Python

If-elif-else

4th bite of Python

Nested loops

5th bite of Python

Input, while, tables

6th bite of Python

Strings

7th bite of Python

Simple maths

8th bite of Python

More loops

9th bite of Python

Dictionaries

10th bite of Python

Drawing

11th bite of Python

Statistics & histograms

12th bite of Python

Pretty nets

13th bite of Python

Medical scans

14th bite of Python

Handwriting recognition

15th bite of Python

Flower recognition