#! /usr/bin/env python
class A(list):
def __init__(self, alist, n):
list.__init__(s elf, alist)
self.n = n
def __str__(self):
return 'AS(%s, %i)' % (list.__str__(s elf), self.n)
def __repr__(self):
return 'AR(%s, %i)' % (list.__repr__( self), self.n)
a = A(['x', 'y'], 7)
print 1, a
print 2, repr(a)
print 3, list.__str__(a)
print 4, list.__repr__(a )
"""
The output is:
1 AS(AR(['x', 'y'], 7), 7)
2 AR(['x', 'y'], 7)
3 AR(['x', 'y'], 7)
4 ['x', 'y']
Why is list.__str__(a) == "AR(['x', 'y'], 7)"?
Note: The problem goes away if "list.__str__(a )" is replaced with
"list.__repr__( self)".
"""
1  1482 
Edward C. Jones wrote: #! /usr/bin/env python
class A(list):
def __init__(self, alist, n):
list.__init__(s elf, alist)
self.n = n
def __str__(self):
return 'AS(%s, %i)' % (list.__str__(s elf), self.n)
def __repr__(self):
return 'AR(%s, %i)' % (list.__repr__( self), self.n)
a = A(['x', 'y'], 7)
print 1, a
print 2, repr(a)
print 3, list.__str__(a)
print 4, list.__repr__(a )
"""
The output is:
1 AS(AR(['x', 'y'], 7), 7)
2 AR(['x', 'y'], 7)
3 AR(['x', 'y'], 7)
4 ['x', 'y']
Why is list.__str__(a) == "AR(['x', 'y'], 7)"?
Because it's coded like this:
def __str__(self):
return repr(self)
That implies str(x) == repr(x), since you don't want that, don't call
list.__str__
Note: The problem goes away if "list.__str__(a )" is replaced with
"list.__repr__( self)".
"""
That's right. You *cannot* call list.__str__ because it contradicts
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