1"""Redo the builtin repr() (representation) but with limits on most sizes."""
2
3__all__ = ["Repr","repr"]
4
5import __builtin__
6from itertools import islice
7
8class Repr:
9
10    def __init__(self):
11        self.maxlevel = 6
12        self.maxtuple = 6
13        self.maxlist = 6
14        self.maxarray = 5
15        self.maxdict = 4
16        self.maxset = 6
17        self.maxfrozenset = 6
18        self.maxdeque = 6
19        self.maxstring = 30
20        self.maxlong = 40
21        self.maxother = 20
22
23    def repr(self, x):
24        return self.repr1(x, self.maxlevel)
25
26    def repr1(self, x, level):
27        typename = type(x).__name__
28        if ' ' in typename:
29            parts = typename.split()
30            typename = '_'.join(parts)
31        if hasattr(self, 'repr_' + typename):
32            return getattr(self, 'repr_' + typename)(x, level)
33        else:
34            s = __builtin__.repr(x)
35            if len(s) > self.maxother:
36                i = max(0, (self.maxother-3)//2)
37                j = max(0, self.maxother-3-i)
38                s = s[:i] + '...' + s[len(s)-j:]
39            return s
40
41    def _repr_iterable(self, x, level, left, right, maxiter, trail=''):
42        n = len(x)
43        if level <= 0 and n:
44            s = '...'
45        else:
46            newlevel = level - 1
47            repr1 = self.repr1
48            pieces = [repr1(elem, newlevel) for elem in islice(x, maxiter)]
49            if n > maxiter:  pieces.append('...')
50            s = ', '.join(pieces)
51            if n == 1 and trail:  right = trail + right
52        return '%s%s%s' % (left, s, right)
53
54    def repr_tuple(self, x, level):
55        return self._repr_iterable(x, level, '(', ')', self.maxtuple, ',')
56
57    def repr_list(self, x, level):
58        return self._repr_iterable(x, level, '[', ']', self.maxlist)
59
60    def repr_array(self, x, level):
61        header = "array('%s', [" % x.typecode
62        return self._repr_iterable(x, level, header, '])', self.maxarray)
63
64    def repr_set(self, x, level):
65        x = _possibly_sorted(x)
66        return self._repr_iterable(x, level, 'set([', '])', self.maxset)
67
68    def repr_frozenset(self, x, level):
69        x = _possibly_sorted(x)
70        return self._repr_iterable(x, level, 'frozenset([', '])',
71                                   self.maxfrozenset)
72
73    def repr_deque(self, x, level):
74        return self._repr_iterable(x, level, 'deque([', '])', self.maxdeque)
75
76    def repr_dict(self, x, level):
77        n = len(x)
78        if n == 0: return '{}'
79        if level <= 0: return '{...}'
80        newlevel = level - 1
81        repr1 = self.repr1
82        pieces = []
83        for key in islice(_possibly_sorted(x), self.maxdict):
84            keyrepr = repr1(key, newlevel)
85            valrepr = repr1(x[key], newlevel)
86            pieces.append('%s: %s' % (keyrepr, valrepr))
87        if n > self.maxdict: pieces.append('...')
88        s = ', '.join(pieces)
89        return '{%s}' % (s,)
90
91    def repr_str(self, x, level):
92        s = __builtin__.repr(x[:self.maxstring])
93        if len(s) > self.maxstring:
94            i = max(0, (self.maxstring-3)//2)
95            j = max(0, self.maxstring-3-i)
96            s = __builtin__.repr(x[:i] + x[len(x)-j:])
97            s = s[:i] + '...' + s[len(s)-j:]
98        return s
99
100    def repr_long(self, x, level):
101        s = __builtin__.repr(x) # XXX Hope this isn't too slow...
102        if len(s) > self.maxlong:
103            i = max(0, (self.maxlong-3)//2)
104            j = max(0, self.maxlong-3-i)
105            s = s[:i] + '...' + s[len(s)-j:]
106        return s
107
108    def repr_instance(self, x, level):
109        try:
110            s = __builtin__.repr(x)
111            # Bugs in x.__repr__() can cause arbitrary
112            # exceptions -- then make up something
113        except Exception:
114            return '<%s instance at %x>' % (x.__class__.__name__, id(x))
115        if len(s) > self.maxstring:
116            i = max(0, (self.maxstring-3)//2)
117            j = max(0, self.maxstring-3-i)
118            s = s[:i] + '...' + s[len(s)-j:]
119        return s
120
121
122def _possibly_sorted(x):
123    # Since not all sequences of items can be sorted and comparison
124    # functions may raise arbitrary exceptions, return an unsorted
125    # sequence in that case.
126    try:
127        return sorted(x)
128    except Exception:
129        return list(x)
130
131aRepr = Repr()
132repr = aRepr.repr
133