Merged revisions 82594,82599 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
........
r82594 | georg.brandl | 2010-07-05 22:13:41 +0200 (Mo, 05 Jul 2010) | 1 line
Update Vec class constructor, remove indirection via function, use operator module.
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r82599 | alexander.belopolsky | 2010-07-05 23:44:05 +0200 (Mo, 05 Jul 2010) | 1 line
"Modernized" the demo a little.
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diff --git a/Demo/classes/Vec.py b/Demo/classes/Vec.py
index 56cb839..b8771ea 100644
--- a/Demo/classes/Vec.py
+++ b/Demo/classes/Vec.py
@@ -1,23 +1,41 @@
-# A simple vector class
-
-
-def vec(*v):
- return Vec(*v)
-
-
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)
- def fromlist(self, v):
+ @classmethod
+ def fromlist(cls, v):
if not isinstance(v, list):
raise TypeError
- self.v = v[:]
- return self
+ inst = cls()
+ inst.v = v
+ return inst
def __repr__(self):
- return 'vec(' + repr(self.v)[1:-1] + ')'
+ args = ', '.join(repr(x) for x in self.v)
+ return 'Vec({0})'.format(args)
def __len__(self):
return len(self.v)
@@ -27,28 +45,24 @@
def __add__(self, other):
# Element-wise addition
- v = map(lambda x, y: x+y, self, other)
- return Vec().fromlist(v)
+ v = [x + y for x, y in zip(self.v, other.v)]
+ return Vec.fromlist(v)
def __sub__(self, other):
# Element-wise subtraction
- v = map(lambda x, y: x-y, self, other)
- return Vec().fromlist(v)
+ v = [x - y for x, y in zip(self.v, other.v)]
+ return Vec.fromlist(v)
def __mul__(self, scalar):
# Multiply by scalar
- v = map(lambda x: x*scalar, self.v)
- return Vec().fromlist(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()