"""Various utility functions.""" from collections import namedtuple, Counter from os.path import commonprefix __unittest = True _MAX_LENGTH = 80 _PLACEHOLDER_LEN = 12 _MIN_BEGIN_LEN = 5 _MIN_END_LEN = 5 _MIN_COMMON_LEN = 5 _MIN_DIFF_LEN = _MAX_LENGTH - \ (_MIN_BEGIN_LEN + _PLACEHOLDER_LEN + _MIN_COMMON_LEN + _PLACEHOLDER_LEN + _MIN_END_LEN) assert _MIN_DIFF_LEN >= 0 def _shorten(s, prefixlen, suffixlen): skip = len(s) - prefixlen - suffixlen if skip > _PLACEHOLDER_LEN: s = '%s[%d chars]%s' % (s[:prefixlen], skip, s[len(s) - suffixlen:]) return s def _common_shorten_repr(*args): args = tuple(map(safe_repr, args)) maxlen = max(map(len, args)) if maxlen <= _MAX_LENGTH: return args prefix = commonprefix(args) prefixlen = len(prefix) common_len = _MAX_LENGTH - \ (maxlen - prefixlen + _MIN_BEGIN_LEN + _PLACEHOLDER_LEN) if common_len > _MIN_COMMON_LEN: assert _MIN_BEGIN_LEN + _PLACEHOLDER_LEN + _MIN_COMMON_LEN + \ (maxlen - prefixlen) < _MAX_LENGTH prefix = _shorten(prefix, _MIN_BEGIN_LEN, common_len) return tuple(prefix + s[prefixlen:] for s in args) prefix = _shorten(prefix, _MIN_BEGIN_LEN, _MIN_COMMON_LEN) return tuple(prefix + _shorten(s[prefixlen:], _MIN_DIFF_LEN, _MIN_END_LEN) for s in args) def safe_repr(obj, short=False): try: result = repr(obj) except Exception: result = object.__repr__(obj) if not short or len(result) < _MAX_LENGTH: return result return result[:_MAX_LENGTH] + ' [truncated]...' def strclass(cls): return "%s.%s" % (cls.__module__, cls.__qualname__) def sorted_list_difference(expected, actual): """Finds elements in only one or the other of two, sorted input lists. Returns a two-element tuple of lists. The first list contains those elements in the "expected" list but not in the "actual" list, and the second contains those elements in the "actual" list but not in the "expected" list. Duplicate elements in either input list are ignored. """ i = j = 0 missing = [] unexpected = [] while True: try: e = expected[i] a = actual[j] if e < a: missing.append(e) i += 1 while expected[i] == e: i += 1 elif e > a: unexpected.append(a) j += 1 while actual[j] == a: j += 1 else: i += 1 try: while expected[i] == e: i += 1 finally: j += 1 while actual[j] == a: j += 1 except IndexError: missing.extend(expected[i:]) unexpected.extend(actual[j:]) break return missing, unexpected def unorderable_list_difference(expected, actual): """Same behavior as sorted_list_difference but for lists of unorderable items (like dicts). As it does a linear search per item (remove) it has O(n*n) performance.""" missing = [] while expected: item = expected.pop() try: actual.remove(item) except ValueError: missing.append(item) # anything left in actual is unexpected return missing, actual def three_way_cmp(x, y): """Return -1 if x < y, 0 if x == y and 1 if x > y""" return (x > y) - (x < y) _Mismatch = namedtuple('Mismatch', 'actual expected value') def _count_diff_all_purpose(actual, expected): 'Returns list of (cnt_act, cnt_exp, elem) triples where the counts differ' # elements need not be hashable s, t = list(actual), list(expected) m, n = len(s), len(t) NULL = object() result = [] for i, elem in enumerate(s): if elem is NULL: continue cnt_s = cnt_t = 0 for j in range(i, m): if s[j] == elem: cnt_s += 1 s[j] = NULL for j, other_elem in enumerate(t): if other_elem == elem: cnt_t += 1 t[j] = NULL if cnt_s != cnt_t: diff = _Mismatch(cnt_s, cnt_t, elem) result.append(diff) for i, elem in enumerate(t): if elem is NULL: continue cnt_t = 0 for j in range(i, n): if t[j] == elem: cnt_t += 1 t[j] = NULL diff = _Mismatch(0, cnt_t, elem) result.append(diff) return result def _count_diff_hashable(actual, expected): 'Returns list of (cnt_act, cnt_exp, elem) triples where the counts differ' # elements must be hashable s, t = Counter(actual), Counter(expected) result = [] for elem, cnt_s in s.items(): cnt_t = t.get(elem, 0) if cnt_s != cnt_t: diff = _Mismatch(cnt_s, cnt_t, elem) result.append(diff) for elem, cnt_t in t.items(): if elem not in s: diff = _Mismatch(0, cnt_t, elem) result.append(diff) return result SIMPAN PERUBAHAN