Identifiers

Identifiers: 

An identifier is a name given to a variable, function, module, or any other object. An identifier is a sequence of characters that can include letters, digits, and underscores (_), but cannot begin with a digit. Here are some rules to keep in mind when choosing identifiers in Python:

• Identifiers are case-sensitive, meaning my_var and my_Var are two different identifiers.
• Identifiers cannot be a keyword, meaning you cannot use a reserved word as an identifier. Examples of keywords in Python include if, else, for, while, and def, among others.
• Identifiers should be descriptive and meaningful, to help make your code easier to understand.
• Identifiers can be any length, although it’s generally a good practice to keep them relatively short and easy to read.

• Identifiers can only contain letters, digits, and underscores. Other characters, such as spaces or special characters, are not allowed.

  Here are some examples of valid and invalid Python identifiers:

  Valid identifiers:
  my_var
  MyVar
  MY_VAR
  my_var_2Top of Form

  Invalid identifiers:
  2_my_var # Cannot begin with a digit
  if # This is a reserved keyword
  my-var # Contains a hyphen instead of and underscore
  my var # Contains a space instead of an underscore