1"""Various utility functions."""
2
3__unittest = True
4
5
6_MAX_LENGTH = 80
7
8
9def safe_repr(obj, short=False):
10    try:
11        result = repr(obj)
12    except Exception:
13        result = object.__repr__(obj)
14    if not short or len(result) < _MAX_LENGTH:
15        return result
16    return result[:_MAX_LENGTH] + ' [truncated]...'
17
18
19def safe_str(obj):
20    try:
21        return str(obj)
22    except Exception:
23        return object.__str__(obj)
24
25
26def strclass(cls):
27    return "%s.%s" % (cls.__module__, cls.__name__)
28
29
30def sorted_list_difference(expected, actual):
31    """Finds elements in only one or the other of two, sorted input lists.
32
33    Returns a two-element tuple of lists.    The first list contains those
34    elements in the "expected" list but not in the "actual" list, and the
35    second contains those elements in the "actual" list but not in the
36    "expected" list.    Duplicate elements in either input list are ignored.
37    """
38    i = j = 0
39    missing = []
40    unexpected = []
41    while True:
42        try:
43            e = expected[i]
44            a = actual[j]
45            if e < a:
46                missing.append(e)
47                i += 1
48                while expected[i] == e:
49                    i += 1
50            elif e > a:
51                unexpected.append(a)
52                j += 1
53                while actual[j] == a:
54                    j += 1
55            else:
56                i += 1
57                try:
58                    while expected[i] == e:
59                        i += 1
60                finally:
61                    j += 1
62                    while actual[j] == a:
63                        j += 1
64        except IndexError:
65            missing.extend(expected[i:])
66            unexpected.extend(actual[j:])
67            break
68    return missing, unexpected
69
70
71def unorderable_list_difference(expected, actual, ignore_duplicate=False):
72    """Same behavior as sorted_list_difference but
73    for lists of unorderable items (like dicts).
74
75    As it does a linear search per item (remove) it
76    has O(n*n) performance.
77    """
78    missing = []
79    unexpected = []
80    while expected:
81        item = expected.pop()
82        try:
83            actual.remove(item)
84        except ValueError:
85            missing.append(item)
86        if ignore_duplicate:
87            for lst in expected, actual:
88                try:
89                    while True:
90                        lst.remove(item)
91                except ValueError:
92                    pass
93    if ignore_duplicate:
94        while actual:
95            item = actual.pop()
96            unexpected.append(item)
97            try:
98                while True:
99                    actual.remove(item)
100            except ValueError:
101                pass
102        return missing, unexpected
103
104    # anything left in actual is unexpected
105    return missing, actual
106