An identifier in Python is a name that is used to identify a variable, function, class, module, or other object. Identifiers can be made up of letters, numbers, and underscores, but they must start with a letter.
Here are some rules for writing identifiers in Python:
- Identifiers cannot start with a digit.
- Identifiers cannot contain spaces.
- Identifiers cannot contain special characters, such as @, #, $, %, etc.
- Identifiers are case-sensitive, meaning that “name” and “Name” are two different identifiers.
Here are some examples of valid identifiers in Python:
Code snippet
name
my_variable
this_is_a_long_identifier
Here are some examples of invalid identifiers in Python:
Code snippet
123name
name_with_space
this_is_a_long_identifier_that_is_too_long
Identifiers are used to make your code more readable and to avoid name collisions. For example, if you have a variable named name
, you can easily see what the variable is used for by looking at its name. Additionally, if you have two functions with the same name, you can easily tell them apart by looking at their function signatures.
I hope this helps!