• IDLE supports debugging
• A simple text mode interactive debugger is also available
• ‘assert’ statement is used to introduce debugging code into a program
• ‘__debug__’ -> built in variable
- the functions surrounded by ‘if __debug__’ will be executed only when ‘__debug__’ is true

Testing of Python

• Python has modules that help a tester in unit testing the code
- docTest – Embedded in the source code
- unittest – separate module
- example

• Logging Errors
- Error stream of the process can be redirected to any file. The stream includes error message and traceback .
- Use sys.excepthook to write your own function to handle unhandled exceptions

Garbage Collection

• Cpython – uses reference count
• Jython – relies on the platform (JVM)

Database API

• Databases supported by Python
- Oracle
- SQL Server
- DB2
- MySQL
- PostgreSQL

• Encapsulation
- By default all class members are public always
- To give private scope to a members, use ’__varname’
• Inheritance
- Supports multiple inheritance
• Overriding attributes
• Examples

Other useful Features

• array : (100,200,300)
• Lists : [42,”Hello”,3.1]
• dictionary : {‘x’:42, ‘y’:3.1}
• Indexing:
L=[1,2,3,4]
L[0] – 1, L[3] – 4
Negative numbers for indexing
L[-1] – 4 (last item)
• Slicing a sequence:
L[1-2] — 2,3

• Cpython (Classic Python)
- coded in C
• Jython
- needs JVM
• Python.NET
- implementation for MS.NET platform
- still in development phase

Python Development Environments

• IDLE
• Source Navigator – by RedHat
• MacPython – for Macintosh
• ActivePython – for Windows
• Commercial IDE
- BlackAdder
- Komodo
- PythonWorks
- MS VS.NET