University:
Boston University
Course:
MET CS 201 | Introduction to Programming
Academic year:

2020
Views:

310

Pages:

9
Author:

saetadzjeg

Tutorial Outline – Part 2       Lists Tuples and dictionaries Modules numpy and matplotlib modules Script setup Development notes Writing Quality Pythonic Code  Cultivating good coding habits pays off in many ways:  Easier and faster to write  Easier and faster to edit, change, and update your code  Other people can understand your work  Python lends itself to readable code  It’s quite hard to write completely obfuscated code in Python.  Exploit language features where it makes sense  Contrast that with this sample of obfuscated C code.  Here we’ll go over some suggestions on how to setup a Python script, make it readable, reusable, and testable. Compare some Python scripts  Open up three files and let’s look at them.  A file that does…something…  bad_code.py  Same code, re-organized:  good_code.py  Same code, debugged, with testing code:  good_code_testing.py Command line arguments  Try to avoid hard-coding file paths, problem size ranges, etc. into your program.  They can be specified at the command line.  Look at the argparse module, part of the Python Standard Library. Tutorial Outline – Part 2       Lists Tuples and dictionaries Modules numpy and matplotlib modules Script setup Development notes Function, class, and variable naming  There’s no word or character limit for names.  It’s ok to use descriptive names for things.  An IDE (like Spyder) will help you fill in longer names so there’s no extra typing anyway.  Give your functions and variables names that reflect their meaning.  Once a program is finished it’s easy to forget what does what where An example development process  Work to develop your program.  Do some flowcharts, work out algorithms, and so on.  Write some Python to try out a few ideas.  Get organized.  Write a “1st draft” version that gets most of what’s needed done.  Move hard-coded values into the if __name__==‘__main__’ section of your code.  Once the code is testing well add command line arguments and remove hardcoded values  Finally (e.g. to run as an SCC batch job) test run from the command line. Spyder command line arguments  Click on the Run menu and choose Configuration per file  Enter command line arguments Python from the command line  To run Python from the command line:  Just type python followed by the script name followed by script arguments.