"Modernized" the demo a little.

This commit is contained in:
Alexander Belopolsky 2010-07-05 21:44:05 +00:00
parent 1f1ccc0386
commit 31c2740760
1 changed files with 30 additions and 16 deletions

View File

@ -1,10 +1,27 @@
# A simple vector class
import operator
class Vec:
""" A simple vector class
Instances of the Vec class can be constructed from numbers
>>> a = Vec(1, 2, 3)
>>> b = Vec(3, 2, 1)
added
>>> a + b
Vec(4, 4, 4)
subtracted
>>> a - b
Vec(-2, 0, 2)
and multiplied by a scalar on the left
>>> 3.0 * a
Vec(3.0, 6.0, 9.0)
or on the right
>>> a * 3.0
Vec(3.0, 6.0, 9.0)
"""
def __init__(self, *v):
self.v = list(v)
@ -17,7 +34,8 @@ class Vec:
return inst
def __repr__(self):
return 'Vec(' + repr(self.v)[1:-1] + ')'
args = ', '.join(repr(x) for x in self.v)
return 'Vec({})'.format(args)
def __len__(self):
return len(self.v)
@ -27,28 +45,24 @@ class Vec:
def __add__(self, other):
# Element-wise addition
v = list(map(operator.add, self, other))
v = [x + y for x, y in zip(self.v, other.v)]
return Vec.fromlist(v)
def __sub__(self, other):
# Element-wise subtraction
v = list(map(operator.sub, self, other))
v = [x - y for x, y in zip(self.v, other.v)]
return Vec.fromlist(v)
def __mul__(self, scalar):
# Multiply by scalar
v = [x*scalar for x in self.v]
v = [x * scalar for x in self.v]
return Vec.fromlist(v)
__rmul__ = __mul__
def test():
a = Vec(1, 2, 3)
b = Vec(3, 2, 1)
print(a)
print(b)
print(a+b)
print(a-b)
print(a*3.0)
import doctest
doctest.testmod()
test()