Python - a study note

Reference : http://www.rexx.com/~dkuhlman/python_book_01.html

• Naming
• Allowed characters in a name: a-z A-Z 0-9 underscore, and must begin with a letter or underscore.
• Names and identifiers are case sensitive.
• Identifiers can be of unlimited length.Special names, customizing, etc. -- Usually begin and end in double underscores.
• Special name classes -- Single and double underscores.
  • Leading double underscores -- Name mangling for method names.
  • Leading single underscore -- Suggests a "private" method name in a class. Not imported by "from module import *".
  • Trailing single underscore -- Sometimes used to avoid a conflict with a keyword, for example, class_.
• Naming conventions -- Not rigid, but here is one set of recommendations:
• Modules and packages -- all lower case.
• Globals and constants -- Upper case.
• Class names -- Bumpy caps with initial upper.
• Method and function names -- All lower case with words separated by underscores.
• Local variables -- Lower case (possibly with underscore between words) or bumpy caps with initial lower or your choice.
• No declaration or data type definition is needed/used.
• Block
• Python represents block structure and nested block structure with indentation, not with begin and end brackets
• The statements which go together must have the same indentation. Each such set of statements is called a block.
• The empty block -- Use the pass no-op statement.
• DocStrings : A doc string is a quoted string at the beginning of a module, function, class, or method.We can use triple-quoting to create doc strings that span multiple lines.
• Doc strings can be viewed with several tools, e.g. help(),obj.__doc__, and, in IPython, a question mark (?) after a name will produce help.
• Statement
• while running:
      guess = int(raw_input('Enter an integer : '))
      if guess == number:
         print 'Congratulations, you guessed it.'
         running = False # this causes the while loop to stop
      elif guess < number:
         print 'No, it is a little higher than that.'
         continue
      else:
         print 'No, it is a little lower than that.'
         break
  else:
      print 'The while loop is over.'
  # Do anything else you want to do here
  print 'Done'
• for i in range(1, 5):
     print i
  else:
     print 'The for loop is over'