The period can also occur in floating-point and imaginary literals. A
sequence of three periods has a special meaning as an ellipsis in slices.
The second half of the list, the augmented assignment operators, serve
lexically as delimiters, but also perform an operation.
The following printing ASCII characters have special meaning as part
of other tokens or are otherwise significant to the lexical analyzer:
' " # \
The following printing ASCII characters are not used in Python. Their
occurrence outside string literals and comments is an unconditional
error:
