Programming

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Goodies / Named Tuple

Normal Class

When you define a class you must type a lot of code. 
 
"""Named tuples
When you define a class you must type a lot of code
Python provides a more concise way with named tuples
"""

class A:
    def __init__(self, x=0, y=0):
        self.x = x
        self.y = y

    def __str__(self):
        return '(%g, %g)' % (self.x, self.y)

from collections import namedtuple
B = namedtuple('B', ['x', 'y'])

a = A(1, 2)
b = B(1, 2)

assert a.x == 1 == b.x
assert a.y == 2 == b.y

print('Tests passed')

Drawback

The drawback is that simple classes don't always stay simple. 
 
"""Named tuples drawback
Simple classes don't always stay simple
To add more methods you need to inherit the named tuple
"""

from collections import namedtuple
A = namedtuple('A', ['x', 'y'])

class B():
    def __init__(self, p):
        self.p = p
        self.x = p.x
        self.y = p.y

    def __str__(self):
        return 'B(%g, %g)' % (self.x, self.y)

a = A(1, 2)
b = B(A(1, 2))

assert a.x == 1 == b.x
assert a.y == 2 == b.y

print('Tests passed')




References