Python: Essential Reference, Third Edition

Identifiers and Reserved Words

An identifier is a name used to identify variables, functions, classes, modules, and other objects. Identifiers can include letters, numbers, and the underscore character (_), but must always start with a nonnumeric character. Letters are currently confined to the characters A–Z and a–z in the ISO-Latin character set. Because identifiers are case sensitive, FOO is different from foo. Special symbols such as $, %, and @ are not allowed in identifiers. In addition, words such as if, else, and for are reserved and cannot be used as identifier names. The following list shows all the reserved words:

and	elif	global	or	yield
assert	else	if	pass
break	except	import	print
class	exec	in	raise
continue	finally	is	return
def	for	lambda ...