(23-06-21)PYTHON FUNDAMENTALS (PART-1)

 

PYHTON CHARACTER SET :

LETTERS : A - Z , a - z

DIGITS : 0 - 9

SPECIAL SYMBOLS : SPACE + - *  /   **  \  ( )  [ ]  { }    //    =  !=  ==  < , > . '  '   " ", ;  :  %  !  &  #  <=  >=   @  _(underscore)

WHITESPACES : BLANK SPACE , TABS , FORMFEED.

OTHER CHARACTERS : IT CAN PROCESS ALL (ASCII) AND  UNICODE  AS PART OF DATA AND LITERALS.

 TOKENS :

THE SMALLEST INDIVIDUAL UNIT IN PROGRAM IS KNOWN AS A TOKEN.

PYTHON HAS FOLLOWING TOKENS : 

1. KEYWORD : A WORD HAVING SPECIAL MEANING RESERVED BY PROGRAMMING LANGUAGE.

EG:- FALSE , ELIF , IN , NOT , IF , AND , TRUE.

2. IDENTIFIERS : IDENTIFEIRS ARE FUNDAMENTAL BUILDING BLOCKS OF  A PROGRAM AND ARE USED AS THE GENERAL TERMINOLOGY FOR THE NAMES GIVEN TO DIFFERENT PARTS OF THE PROGRAM.

EG:-   1)  FIRST CHARACTER MUST BE A LETTER

           2)  UNDERSCORE(_) COUNTS AS A LETTER

           3)  IDENTIFIER MUST NOT BE  A KEYWORD OF PYTHON

           4)  PYTHON IS CASE SENSITIVE

           5)  AN IDENTIFIER CANNOT CONTAIN A SPECIAL CHARACTER EXCEPT FOR                                UNDERSCOR(_)

3. LITERALS / VALUES : LITERALS OR VALUES ARE THE DATA TYPES THAT HAVE A FIXED VALUE.

                                            TYPES OF LITERALS

(1) STRING LITERALS

(2) NUMERIC LITERALS

(3) BOOLEAN LITERALS

 

STRING LITERALS:::::

THE TEXT ENCLOSED IN QUOTES FORMS A STRING LITERAL IN PYTHON

EG:- 

"KHUSHI"

"INFORMATICS PRACTICES"

NUMERIC LITERALS::::

NUMERIC WE HAVE 2 DIFFRENT TYPES:

1) INT- POSITIVE OR NEGATIVE WITH NO DECIMAL PLACES

2) FLOAT- REAL NUMBERS WITH A DECIMAL POINT

BOOLEAN LITERALS:::::

A BOLLEAN LITERAL IN PYTHON IS USED TO PRESENT ONE OF THE TWO BOOLEAN VALUES --> 1)TRUE                  2)FALSE.