repr.py 4.2 KB

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