time_slots_classes_dataclasses.py

''' comparing speed of new dataclass 
    with standard class attributes and slots, 
    running in 3.7.0b1'''

# subscribe to me: https://www.youtube.com/user/gjenkinslbcc?sub_confirmation=1
# I recommend reading PEP557: https://www.python.org/dev/peps/pep-0557/
# this code at gist: http://bit.ly/slotsVdatclass

from dataclasses import dataclass
from timeit import timeit

def _str(p): return f'({p.x}, {p.y}, {p.z})' # shared str()


class PointStdClass: # standard class
    def __init__(self, x=0.0, y=0.0, z=0.0):
        self.x, self.y, self.z = x, y, z

    def __str__(self): return _str(self)
    
    
class PointSlots: # slots based class
    __slots__ = 'x','y','z'
    def __init__(self, x=0.0, y=0.0, z=0.0):
        self.x, self.y, self.z = x, y, z
    
    def __str__(self): return _str(self)
  
  
@dataclass
class PointDataClass: # DataClass based class, note __init__ is predefined, see PEP557 for more predefined
    x: float = 0.0
    y: float = 0.0
    z: float = 0.0

    def __str__(self): return _str(self)


# create some of each
c1, c2 = PointStdClass(), PointStdClass(1.0, 2.0, 3.0)
s1, s2 = PointSlots(), PointSlots(1.0, 2.0, 3.0)
dc1, dc2 = PointDataClass(), PointDataClass(1.0, 2.0, 3.0)
 
# print them  
print(c1, c2)
print(s1,s2)
print(dc1, dc2)

# timeit: create instance, access, assignment    

print('\nPoint object Creation:')
t_class = timeit('PointStdClass()',setup='from __main__ import PointStdClass')
t_slots = timeit('PointSlots()',setup='from __main__ import PointSlots')
t_dataclass = timeit('PointDataClass()',setup='from __main__ import PointDataClass')
print(f'  standard class: {t_class:.6f}')
print(f'  slots class   : {t_slots:.6f}')
print(f'  dataclass     : {t_dataclass:.6f}')

print('\nPoint attribute access:')
t_class = timeit('p.x',setup='from __main__ import PointStdClass; p = PointStdClass()')
t_slots = timeit('p.x',setup='from __main__ import PointSlots; p = PointSlots()')
t_dataclass = timeit('p.x',setup='from __main__ import PointDataClass; p = PointDataClass()')
print(f'  standard class: {t_class:.6f}')
print(f'  slots class   : {t_slots:.6f}')
print(f'  dataclass     : {t_dataclass:.6f}')

print('\nPoint attribute assignment:')
t_class = timeit('p.x = 9.0',setup='from __main__ import PointStdClass; p = PointStdClass()')
t_slots = timeit('p.x = 9.0',setup='from __main__ import PointSlots; p = PointSlots()')
t_dataclass = timeit('p.x = 9.0',setup='from __main__ import PointDataClass; p = PointDataClass()')
print(f'  standard class: {t_class:.6f}')
print(f'  slots class   : {t_slots:.6f}')
print(f'  dataclass     : {t_dataclass:.6f}')

print()