fluentpython-example-code/attic/iterables/vector_flex_init.py at master · stly/fluentpython-example-code

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"""

A more flexible `__init__` for the Vector class

A Vector can be built from an iterable:

>>> Vector([10, 20, 30])

Vector(10, 20, 30)

>>> Vector(range(1, 5))

Vector(1, 2, 3, 4)

Or from two more arguments:

>>> Vector(100, 200)

Vector(100, 200)

>>> Vector(1, 2, 3, 4, 5)

Vector(1, 2, 3, 4, 5)

One-dimensional vectors are not supported:

>>> Vector(99)

Traceback (most recent call last):

...

TypeError: Vector() takes one iterable argument or at least 2 scalar arguments

"""

import reprlib

class Vector:

"""An n-dimensional vector"""

def __init__(self, first, *rest): # <1>

if rest:

self._components = (first,) + tuple(rest) # <3>

else:

try:

self._components = tuple(first) # <2>

except TypeError:

raise TypeError('Vector() takes one iterable argument or at least 2 scalar arguments')

def __repr__(self):

return 'Vector' + reprlib.repr(self._components)