We're back after a server migration that caused effbot.org to fall over a bit harder than expected. Expect some glitches.

Identifiers

Identifiers (also referred to as names) consists of at least one letter or underscore, followed by any number of letters, digits, or underscores.

The identifier syntax is described by the following lexical definitions:

identifier ::= ([letter][1]|"\_") ([letter][1] | [ digit][2] | "\_")\*
letter ::= [ lowercase][3] | [uppercase][4]
lowercase ::= "a"..."z"
uppercase ::= "A"..."Z"
digit ::= "0"..."9"

Identifiers are unlimited in length. Case is significant.

Certain identifiers are reserved by the language; see keywords for a complete list. In addition, certain identifier patterns have special meaning for user application; see reserved-identifier-classes.