#02 - Naming A Variable

Coming to naming of a variable, there are certain rules to name a variable ... let's see what are them

1. We cannot use keyword as a varibale name.
   So, what is a keyword ? A keyword is nothing but a word which has specific definition for it or which are predefined by the interpreter
   some of the key words are followed:
   if, else, elif, sum, list, tuple, int, float , bool, class, def, break ,continue, pass , try, except ,etc....


2. We can use alphabets to name our variable (from a-z and A-Z)


3. We can have numbers in our name of the variable
   we can use numbers from 0 - 9
   NOTE: we cannot use numbers in the beginning of a variable like (0num, 234adre, 007number) these are not valid variables


4. We can use (_) underscore in our name of the varibale
   NOTE: we can use _ anywhere i.e. in the starting of a variable in middle of a variable and at the ending of a variable

So any variable name satisfies all the 4 conditions are valid variables

Example:

VALID:

1. num
2. num_2
3. num3
4. _num
5. n_u_m
6. Num4

INVALID:

1. 0num - number at the beginning of the name
2. sum - cannot use keywords in name
3. -num - special character (-) is not allowed
4. $dun - sepcial character ($) is not allowed
5. class - keywords are not allowed

NOTE: Num and num are treated diffetent because python is a case sensitive language, which means N and n are treated differently