Python Identifiers

Identifiers are the names that are given to the various program elements such as functions, class, variables, list, tuple etc.

They are defined to give a unique name to an entity to identify it during the run time of the program.

There are some rules for making an identifier in python -

  • The first character of an identifier must be an alphabet or underscore.For example -
var = 0
_var = 0
var = 0

Three of them  are valid identifiers in python.

  • The identifiers are not allowed to declare a variable name  starts with the digit. For example :-

The above declaration will  raise a syntax error.

  • It must not be a reserved word of python language. For example -
pass = 78

 In this case pass is a keyword of python language so this is invalid declaration.

  • The identifier name must avoid special symbols other than underscore and white spaces. For example -
Codie ns = 90

The given identifier is invalidand it will raise an error.

  • Python identifiers are case-sensitive that means lowercase and uppercase both are different. For example -

Here, i and I both are different and  are stored in different memory locations.