Basics of Python Programming

Basics of Python Programming

1. History

   • It was created by 'GUIDO VAN ROSSUM' in late 1980 at National Research Institute in the Netherland

2. Two modes

   • Interactive mode
     • It allows us to interactively write one statement at a time and get the output
   • Script mode
     • In this mode, we type program in a file and use interpreter to translate the content of the file.

3. Python Character set

   • Letters (A-Z, a-z)
   • Digits (0-9)
   • Special symbols (Space, + - / * / [ ] ( )... etc
   • Whitespaces (Blank Space, tabs ...)
   • Other ASCII characters
   • Definition
     • It is a set of valid characters that a language can recognize.

4. Tokens

   • Definition
     • Smallest individual units in a program
   • Keywords
     • A keyword is a word having special meaning reserved by programming language. eg: int, if, for etc.
   • Identifiers
     • Identifiers are fundamental building blocks of a program and are used as a general terminology for the names given to different parts of the program viz, variables, objects, fucntions etc.
   • Literals
     • Numeric Literals
       • integer literals
       • Floating point literals
     • String Literals
       • Single line strings - represented by single quotes or double quotes
       • Multiline strings
         • By adding backslash at the end of normal single/ double quote strings
         • Typing text in triple quotes
     • Boolean Literals
       • True
       • False
     • Special Literal- None
     • Definition
       • Refers to constant Value
   • Operators
     • Binary Operator
     • Unary Operator
   • Punctuators
     • Punctuators are symbols that are used in programming languages to organise programming sentence structures, and indicate the rhythm and empasis of expressions, statements and program structure

5. Barebones of Python Program

   • Statements
     • Instruction that does something i.e some action takes place
   • Comments
     • Single line comment
     • Multiline Comment
   • Function
     • Code that has name and it can be reused
   • Expressions
     • Any legal combination of symbols that represents a value
   • Blocks and indentation
     • Python uses indentation to create blocks of code.