Mercurial > cpython-lru_cache-weakref
annotate Demo/classes/Vec.py @ 4566:6403c94de50d legacy-trunk
Added safeguard against failure in __del__.
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Wed, 27 Nov 1996 19:39:58 +0000 |
| parents | 8701b93383ab |
| children | 558689b6d7f0 |
| rev | line source |
|---|---|
| 945 | 1 # A simple vector class |
| 2 | |
| 3 | |
| 4 def vec(*v): | |
|
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8701b93383ab
*** empty log message ***
Guido van Rossum <guido@python.org>
parents:
945
diff
changeset
|
5 return apply(Vec, v) |
| 945 | 6 |
| 7 | |
| 8 class Vec: | |
| 9 | |
|
1427
8701b93383ab
*** empty log message ***
Guido van Rossum <guido@python.org>
parents:
945
diff
changeset
|
10 def __init__(self, *v): |
| 945 | 11 self.v = [] |
| 12 for x in v: | |
| 13 self.v.append(x) | |
| 14 | |
| 15 | |
| 16 def fromlist(self, v): | |
| 17 self.v = [] | |
| 18 if type(v) <> type([]): | |
| 19 raise TypeError | |
| 20 self.v = v[:] | |
| 21 return self | |
| 22 | |
| 23 | |
| 24 def __repr__(self): | |
| 25 return 'vec(' + `self.v`[1:-1] + ')' | |
| 26 | |
| 27 def __len__(self): | |
| 28 return len(self.v) | |
| 29 | |
| 30 def __getitem__(self, i): | |
| 31 return self.v[i] | |
| 32 | |
| 33 def __add__(a, b): | |
| 34 # Element-wise addition | |
| 35 v = [] | |
| 36 for i in range(len(a)): | |
| 37 v.append(a[i] + b[i]) | |
| 38 return Vec().fromlist(v) | |
| 39 | |
| 40 def __sub__(a, b): | |
| 41 # Element-wise subtraction | |
| 42 v = [] | |
| 43 for i in range(len(a)): | |
| 44 v.append(a[i] - b[i]) | |
| 45 return Vec().fromlist(v) | |
| 46 | |
| 47 def __mul__(self, scalar): | |
| 48 # Multiply by scalar | |
| 49 v = [] | |
| 50 for i in range(len(self.v)): | |
| 51 v.append(self.v[i]*scalar) | |
| 52 return Vec().fromlist(v) | |
| 53 | |
| 54 | |
| 55 | |
| 56 def test(): | |
| 57 a = vec(1, 2, 3) | |
| 58 b = vec(3, 2, 1) | |
| 59 print a | |
| 60 print b | |
| 61 print a+b | |
| 62 print a*3.0 | |
| 63 | |
| 64 test() |