Python – Basics -1

Identifiers - Python is a case sensitive programming language. The words man and Man are two different identifies in python.

An Identifier is a name used to identify a variable, function, class, module or other object. An identifier starts with a letter A to Z or a to z or an underscore (_) followed by zero or more letters, underscores and digits (0 to 9)

Python does not allow punctuation characters such as @, $, and % within identifiers.

Here are the naming Conventions in Python

• Class Names start with an Upper Case Letter
• All other Identifiers start with a Lower Case Letter
• Starting an Identifier with a Under-Score indicates that identifier is Private
• Starting an Identifier with 2 Under-Scores indicates a strongly private Identifier
• We all see a Identifier with 2 tailing under-Scores which means they are language defined special names

Indentation – Python does not use a semi-colon of closing braces for statement end. Blocks of statements or class and function definitions are identified by using indentation.

The Indentation is rigidly enforced.  The number of spaces in the indentation is variable, but all statements within the block must be indented the same amount.

So all the continuous lines indented with same number of spaces would form a block.

Comments - A hash sign (#) that is not inside a string literal begins a comment.

Quotation - Python accepts single ('), double (") and triple (''' or """) quotes to denote string literals, as long as the same type of quote starts and ends the string.

Reserved Words - Python does contain reserved words for internal language structure. These reserved works cannot be used with an constant or variable or any identifier names. Here are the lists of the reserved words available in Python

And	exec	Not
Assert	finally	or
Break	for	pass
Class	from	print
Continue	global	raise
def	if	return
del	import	try
elif	in	while
else	is	with
except	lambda	yield

Suites – A group of individual statement which makes a single code block are called suites. Normally compound statements like if, else, while etc requires a header line and a Suite like

if expression :

   suite

elif expression :

   suite

else :

   suite