ref: 065c3557af8de1b20d94c2e86a4a29c5d33ccc67
dir: /sys/src/cmd/python/Demo/classes/Vec.py/
# A simple vector class def vec(*v): return Vec(*v) class Vec: def __init__(self, *v): self.v = list(v) def fromlist(self, v): if not isinstance(v, list): raise TypeError self.v = v[:] return self def __repr__(self): return 'vec(' + repr(self.v)[1:-1] + ')' def __len__(self): return len(self.v) def __getitem__(self, i): return self.v[i] def __add__(self, other): # Element-wise addition v = map(lambda x, y: x+y, self, other) return Vec().fromlist(v) def __sub__(self, other): # Element-wise subtraction v = map(lambda x, y: x-y, self, other) return Vec().fromlist(v) def __mul__(self, scalar): # Multiply by scalar v = map(lambda x: x*scalar, self.v) return Vec().fromlist(v) 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 test()