Python-2

Creating Comments in Python

Single Line Comment:  Comments starts with a #








We can write comments at the beginning or at the end .  




Multiline Comments


























Variable Declaration

Rules for variable declaration

• A variable name must start with a letter or the underscore character
• A variable name cannot start with a number
• A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
• Variable names are case-sensitive (age, Age and AGE are three different variables)
• A variable name cannot be any of the Python Keyword.

Invalid Variables Declarations Names

Data Types

Python Numeric Data Type

Int

Int, or integer, is a whole number, positive or negative, without decimals, of unlimited length.

Float

Float, or "floating point number" is a number, positive or negative, containing one or more decimals.

Float can also be scientific numbers with an "e" to indicate the power of 10

Complex

Complex numbers are written with a "j" as the imaginary part:

Boolean Type

If an expression is True or False.

The bool() function allows you to evaluate any value, and give you   True or False in return,

Any string is True, except empty strings.

Any number is True, except 0.

Any list, tuple, set, and dictionary are True, except empty ones.

  

The following with return False 

Note : Functions can return Boolean values as well.

Example

String Data Type

We can use single quotation marks, or double quotation marks.

'uday' or "uday".

Multiline Strings:

You can assign a multiline string to a variable by using three quotes: