NamedTuplesDocstring.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Thu Mar 11 10:43:28 2021

@author: maherme
"""
#%%
# We have some help for the namedtuple:

from collections import namedtuple

Point2D = namedtuple('Point2D', 'x y')

print(Point2D.__doc__)
print(Point2D.x.__doc__)
print(Point2D.y.__doc__)

#%%

help(Point2D)

#%%
# This properties can be overwritten:

Point2D.__doc__ = '2D Cartesian coordinate'
Point2D.x.__doc__ = 'x coordinate'
Point2D.y.__doc__ = 'y coordinate'

print(Point2D.__doc__)
print(Point2D.x.__doc__)
print(Point2D.y.__doc__)

#%%
# We can use prototype for creating default values:

Vector2D = namedtuple('Vector2D', 'x1 y1 x2 y2 origin_x origin_y')
print(Vector2D._fields)
v1 = Vector2D(0, 0, 10, 10, 0, 0)
print(v1)

# We create a vector_zero as prototype:
vector_zero = Vector2D(0, 0, 0, 0, 0, 0)
print(vector_zero)

v2 = vector_zero._replace(x1=10, y1 = 10, x2=20, y2=20)
print(v2)

#%%
# Other way to do this:
    
def func(a, b=10, c=20):
    print(a, b, c)
    
func(1)
print(func.__defaults__)
func.__defaults__ = (100, 200, 300)
print(func())

#%%
# You can also modify the default inside the new method:

Vector2D.__new__.__defaults__ = (0, 0)
v1 = Vector2D(10, 10, 20, 20)
print(v1)
Vector2D.__new__.__defaults__ = (-10, -10)
v1 = Vector2D(10, 10, 20, 20)
print(v1)
Vector2D.__new__.__defaults__ = (-10, -10, -10, -10)
v1 = Vector2D(10, 10)
print(v1)

#%%