Floating Point Objects

Working with Python float type

Overview

Python floats are implemented as C double precision floating-point numbers.

Type Object

PyTypeObject PyFloat_Type

Type Checking

int PyFloat_Check(PyObject *p)
int PyFloat_CheckExact(PyObject *p)

Creating Floats

PyObject* PyFloat_FromDouble(double v)
PyObject* PyFloat_FromString(PyObject *str)

Example:

PyObject *pi = PyFloat_FromDouble(3.14159);
return pi;

Converting to C double

double PyFloat_AsDouble(PyObject *pyfloat)

Example:

double value = PyFloat_AsDouble(obj);
if (value == -1.0 && PyErr_Occurred())
    return NULL;

Special Values

Py_RETURN_NAN  // Return NaN
Py_RETURN_INF(sign)  // Return infinity

Example:

if (is_invalid(x))
    Py_RETURN_NAN;

See Also

• Integer Objects
• Object Protocol