Introduction to Python !!

Introduction to Python !!

Python is that one particular language which is gaining popularity day by day!! I have started learning this language and welcome you all to join my journey; where I'll be documenting my notes in the form of a blog for all of us. This is the first article in Python for Beginners series. So, let's get started!!!

Python is an interactive programming language. Popularity : Simple syntax which make programs easy to read and write!!

IDLE - Integrated Development and Learning Environment It is an interpreter for python consisting of a python shell and python editor.

  • Python editor - allows us to work in a script mode.
  • Python shell - an interactive interpreter in which code is written at the >>> prompt and with a press of ENTER key, it responds with the computation result. For example Capture.PNG The text to be printed is enclosed within ' ' which do not get displayed in the output. The >>> prompt indicates that the shell is waiting for a user command.

Python as Calculator - arithmetic operators

Operators used in python are :

  • + to print the sum of operands.
  • - to print the subtraction result of operands. It is also used as the negation operator to print the negative value of an input.
  • * to print the product of operands.
  • / to print the division result of operands which will always be a real number ( fraction or decimal).
  • // to print the division result of operands which will be an integer (non-fraction or non-decimal). To print a real number, either one of the operands must be a real number.
  • % to print the remainder of the division of operands (modulus)
  • ** to print the exponential result of operands (to the power of ) Capture.PNG

Associativity of operators

A property that determines the evaluation of operators of the same precedence.

  • Left associativity : The operators are evaluated from left to right in an expression.
  • Right associativity : The operators are evaluated from right to left in an expression. All the operators except the exponentiation operator ** are evaluated from left associative operators. The ** operator is a right associative operator.

Capture.PNG

The first example 2 ** 3 gets evaluated as 2 ^ 3 i.e. 8.

The second example 3 ** 2 ** 2 gets evaluated as 3 ** (2 ** 2) i.e 3 ** 4 i.e. 81.

Precedence of arithmetic operators

( ) Parenthesis

** Exponentiation

- Negation

/ Division // Integer division * Multiplication % Modulus

+ Addition - Subtraction

This order of precedence decreases from top to bottom i.e. parenthesis have the highest precedence whereas subtraction operation has the lowest!

Finishing off with the the arithmetic operators, I will be starting with the logical and relational operators in the next blog. Till then, try out these concepts and play with the operators to understand better!!