README.md

Python language issues

This repo contains Python practical examples of certain topics like:

• Classes

  • Inheritance

• Class Methods

  • Method overriding in runtine
  • Abstract methods
  • Static methods
  • var-args methods
  • dictionary-typed arguments in methods
  • mixed method types (var-args + kw-args)
  • using global variables inside methods
  • mutable arguments (changed with each call) in methods like on example below

    def mutableArgsWarn(self, x=[]):
        print "--- mutableArgsWarn ---"
        x.append(1)
        print x

• Console usage examples

• Using of different data types:

  • Descriptors example1,
  • Descriptors example2
  • Dictionaries
  • Generators
  • Lists
  • Strings
  • Sets
  • Tuples
  • Enforcing method parameter type

• Formatting date:

    print datetime.now().strftime("%Y-%m-%d %H:%M:%S")

• Parsing date from string:

    print datetime.strptime('Wed, 27 Oct 1770 22:17:00', '%a, %d %b %Y %H:%M:%S')

• Determining difference between two dates using timedelta

   print "another year:",timedelta(weeks=40, days=84, hours=23, minutes=50, seconds=600)

• Debugging using special variables builtin, sys, inspect

• Handling and throwing exceptions:

  • using raise
  • using try-except construct
  • creating user-defined exceptions

• File operations

  • examples of common file operations: read, write, delete, close
  • saving objects to files in JSON format
  • serializing and saving objects
  • example of changing file names using regular expressions

• Flow Control

  • using comprehensions
  • examples of the different loop types: for in, while
  • using ternary operator

• Profiling code

  • using of timeit module to determine execution time of different variants of
  • using of unittest

• Regular Expressions

  • matching the pattern using re.match
  • finding all occurences of the pattern with re.findall
  • iterate over matched results using re.finditer
  • splitting string using regular expressions with re.split
  • substituting the pattern using re.sub
  • display matched results using match.group and match.groups

• Special Python features

  • Overriding operators using: lt, le, eq, ne, gt, ge
  • Using function decorators (and simple explanation how this works)
  • Defining descriptor classes (If class defines methods get, set, delete it's called descriptor)
  • different using of import statement (wildcards, relative imports)
  • overriding built-in functions: example of how override print function
  • example of how to override mathematical operators behavior in classes

• Python tricks

  • in-place values swapping
  • chaining of comparison operators
  • using generators with yield keyword
  • create classes on-the-fly

• Special class methods examples: init,new,del,repr,str,getattr,cal

• Urllib example usage in GET and POST requests (how to easy make get/post requests)