Python Language Reference Manualby Guido van Rossum and Fred L. Drake, Jr. Paperback (6"x9"), 120 pages ISBN 0954161785 RRP £12.95 ($19.95) Sales of this book support the Python Software Foundation! Get a printed copy>>> |

### 2.4.5 Floating point literals

Floating point literals are described by the following lexical definitions:

`floatnumber`

`pointfloat`

|`exponentfloat`

`pointfloat [`

`intpart`

]`fraction`

|`intpart`

"."`exponentfloat (`

`intpart`

|`pointfloat`

)`exponent`

`intpart`

`digit`

+`fraction "."`

`digit`

+`exponent ( "e" | "E" ) [ "+" | "-" ]`

`digit`

+

Note that the integer and exponent parts of floating point numbers
can look like octal integers, but are interpreted using radix 10. For
example, `‘077e010’` is legal, and denotes the same number
as `‘77e10’`.
The allowed range of floating point literals is
implementation-dependent.
Some examples of floating point literals:

3.14 10. .001 1e100 3.14e-10 0e0

Note that floating-point literals do not include a sign; a phrase like
`-1.0`

is actually an expression composed of the unary operator
`-`

and the literal `1.0`

.

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