In [1]:

    

%load_ext Cython


    

In [2]:

    

# Pure Python version
class Particle(object):
    """Simple Particle type."""
    def __init__(self, m, x, v):
        self.mass = m
        self.position = x
        self.velocity = v
    def get_momentum(self):
        return self.mass * self.velocity


    

In [3]:

    

%%cython
cdef class cParticle(object):
    """Simple Particle type."""
    cdef double mass, position, velocity
    def __init__(self, m, x, v):
        self.mass = m
        self.position = x
        self.velocity = v
    def get_momentum(self):
        return self.mass * self.velocity


    

In [4]:

    

Particle?


    

In [5]:

    

cParticle?


    

In [6]:

    

py_particle = Particle(1.0, 2.0, 3.0)


    

In [7]:

    

cy_particle = cParticle(1.0, 2.0, 3.0)


    

In [8]:

    

py_particle.get_momentum()


    

    
Out[8]:





3.0

In [9]:

    

cy_particle.get_momentum()


    

    
Out[9]:





3.0

In [10]:

    

py_particle.mass


    

    
Out[10]:





1.0

In [11]:

    

cy_particle.mass


    

    




---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-11-a9e7785817af> in <module>()
----> 1 cy_particle.mass

AttributeError: '_cython_magic_4bf2e919ad94f6d2445c923510fe4893.cPa' object has no attribute 'mass'

In [12]:

    

py_particle.charge = 1


    

In [14]:

    

py_particle.__dict__


    

    
Out[14]:





{'charge': 1, 'mass': 1.0, 'position': 2.0, 'velocity': 3.0}

In [15]:

    

cy_particle.charge = 1


    

    




---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-15-2be780edcd30> in <module>()
----> 1 cy_particle.charge = 1

AttributeError: '_cython_magic_4bf2e919ad94f6d2445c923510fe4893.cParticle' object has no attribute 'charge'