From bdaad8c93978b22fca49cb4eeea8cdea3610bafd Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Sat, 9 Apr 2005 14:55:07 +0000
Subject: * Fix error in definition of Im() which returned self instead of 0
for non-complex arguments.
* Replace type() comparisons with isinstance() checks.
* Replace apply() calls with equivalent syntactic form.
* Simplify __hash__ definition to hash the underlying tuple.
* Use math.hypot() for more robust computation of __abs__().
* Use sorted() instead of the multi-step keys/sort/iter.
* Update comment on the cmath module.
---
Demo/classes/Complex.py | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/Demo/classes/Complex.py b/Demo/classes/Complex.py
index 03c93fd..2b306ad 100755
--- a/Demo/classes/Complex.py
+++ b/Demo/classes/Complex.py
@@ -54,7 +54,7 @@
# nor are shift and mask operations.
#
# The standard module math does not support complex numbers.
-# (I suppose it would be easy to implement a cmath module.)
+# The cmath modules should be used instead.
#
# Idea:
# add a class Polar(r, phi) and mixed-mode arithmetic which
@@ -62,7 +62,7 @@
# Complex for +,-,cmp
# Polar for *,/,pow
-import types, math
+import math
import sys
twopi = math.pi*2.0
@@ -74,8 +74,8 @@ def IsComplex(obj):
def ToComplex(obj):
if IsComplex(obj):
return obj
- elif type(obj) == types.TupleType:
- return apply(Complex, obj)
+ elif isinstance(obj, tuple):
+ return Complex(*obj)
else:
return Complex(obj)
@@ -86,14 +86,12 @@ def PolarToComplex(r = 0, phi = 0, fullcircle = twopi):
def Re(obj):
if IsComplex(obj):
return obj.re
- else:
- return obj
+ return obj
def Im(obj):
if IsComplex(obj):
return obj.im
- else:
- return obj
+ return 0
class Complex:
@@ -119,9 +117,9 @@ class Complex:
raise TypeError, 'Complex numbers are immutable'
def __hash__(self):
- if not self.im: return hash(self.re)
- mod = sys.maxint + 1L
- return int((hash(self.re) + 2L*hash(self.im) + mod) % (2L*mod) - mod)
+ if not self.im:
+ return hash(self.re)
+ return hash((self.re, self.im))
def __repr__(self):
if not self.im:
@@ -142,8 +140,7 @@ class Complex:
return self
def __abs__(self):
- # XXX could be done differently to avoid overflow!
- return math.sqrt(self.re*self.re + self.im*self.im)
+ return math.hypot(self.re, self.im)
def __int__(self):
if self.im:
@@ -238,8 +235,8 @@ def checkop(expr, a, b, value, fuzz = 1e-6):
except:
result = sys.exc_type
print '->', result
- if (type(result) == type('') or type(value) == type('')):
- ok = result == value
+ if isinstance(result, str) or isinstance(value, str):
+ ok = (result == value)
else:
ok = abs(result - value) <= fuzz
if not ok:
@@ -312,13 +309,11 @@ def test():
(Complex(1), Complex(0,10), 1),
],
}
- exprs = testsuite.keys()
- exprs.sort()
- for expr in exprs:
+ for expr in sorted(testsuite):
print expr + ':'
t = (expr,)
for item in testsuite[expr]:
- apply(checkop, t+item)
+ checkop(*(t+item))
if __name__ == '__main__':
--
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