projects / OpenSPARC-T2-SAM / blame
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| 920dae64 AT |
1 | # Author: Fred L. Drake, Jr. |
| 2 | # fdrake@acm.org | |
| 3 | # | |
| 4 | # This is a simple little module I wrote to make life easier. I didn't | |
| 5 | # see anything quite like it in the library, though I may have overlooked | |
| 6 | # something. I wrote this when I was trying to read some heavily nested | |
| 7 | # tuples with fairly non-descriptive content. This is modeled very much | |
| 8 | # after Lisp/Scheme - style pretty-printing of lists. If you find it | |
| 9 | # useful, thank small children who sleep at night. | |
| 10 | ||
| 11 | """Support to pretty-print lists, tuples, & dictionaries recursively. | |
| 12 | ||
| 13 | Very simple, but useful, especially in debugging data structures. | |
| 14 | ||
| 15 | Classes | |
| 16 | ------- | |
| 17 | ||
| 18 | PrettyPrinter() | |
| 19 | Handle pretty-printing operations onto a stream using a configured | |
| 20 | set of formatting parameters. | |
| 21 | ||
| 22 | Functions | |
| 23 | --------- | |
| 24 | ||
| 25 | pformat() | |
| 26 | Format a Python object into a pretty-printed representation. | |
| 27 | ||
| 28 | pprint() | |
| 29 | Pretty-print a Python object to a stream [default is sys.stdout]. | |
| 30 | ||
| 31 | saferepr() | |
| 32 | Generate a 'standard' repr()-like value, but protect against recursive | |
| 33 | data structures. | |
| 34 | ||
| 35 | """ | |
| 36 | ||
| 37 | import sys as _sys | |
| 38 | ||
| 39 | from cStringIO import StringIO as _StringIO | |
| 40 | ||
| 41 | __all__ = ["pprint","pformat","isreadable","isrecursive","saferepr", | |
| 42 | "PrettyPrinter"] | |
| 43 | ||
| 44 | # cache these for faster access: | |
| 45 | _commajoin = ", ".join | |
| 46 | _id = id | |
| 47 | _len = len | |
| 48 | _type = type | |
| 49 | ||
| 50 | ||
| 51 | def pprint(object, stream=None, indent=1, width=80, depth=None): | |
| 52 | """Pretty-print a Python object to a stream [default is sys.stdout].""" | |
| 53 | printer = PrettyPrinter( | |
| 54 | stream=stream, indent=indent, width=width, depth=depth) | |
| 55 | printer.pprint(object) | |
| 56 | ||
| 57 | def pformat(object, indent=1, width=80, depth=None): | |
| 58 | """Format a Python object into a pretty-printed representation.""" | |
| 59 | return PrettyPrinter(indent=indent, width=width, depth=depth).pformat(object) | |
| 60 | ||
| 61 | def saferepr(object): | |
| 62 | """Version of repr() which can handle recursive data structures.""" | |
| 63 | return _safe_repr(object, {}, None, 0)[0] | |
| 64 | ||
| 65 | def isreadable(object): | |
| 66 | """Determine if saferepr(object) is readable by eval().""" | |
| 67 | return _safe_repr(object, {}, None, 0)[1] | |
| 68 | ||
| 69 | def isrecursive(object): | |
| 70 | """Determine if object requires a recursive representation.""" | |
| 71 | return _safe_repr(object, {}, None, 0)[2] | |
| 72 | ||
| 73 | class PrettyPrinter: | |
| 74 | def __init__(self, indent=1, width=80, depth=None, stream=None): | |
| 75 | """Handle pretty printing operations onto a stream using a set of | |
| 76 | configured parameters. | |
| 77 | ||
| 78 | indent | |
| 79 | Number of spaces to indent for each level of nesting. | |
| 80 | ||
| 81 | width | |
| 82 | Attempted maximum number of columns in the output. | |
| 83 | ||
| 84 | depth | |
| 85 | The maximum depth to print out nested structures. | |
| 86 | ||
| 87 | stream | |
| 88 | The desired output stream. If omitted (or false), the standard | |
| 89 | output stream available at construction will be used. | |
| 90 | ||
| 91 | """ | |
| 92 | indent = int(indent) | |
| 93 | width = int(width) | |
| 94 | assert indent >= 0, "indent must be >= 0" | |
| 95 | assert depth is None or depth > 0, "depth must be > 0" | |
| 96 | assert width, "width must be != 0" | |
| 97 | self._depth = depth | |
| 98 | self._indent_per_level = indent | |
| 99 | self._width = width | |
| 100 | if stream is not None: | |
| 101 | self._stream = stream | |
| 102 | else: | |
| 103 | self._stream = _sys.stdout | |
| 104 | ||
| 105 | def pprint(self, object): | |
| 106 | self._stream.write(self.pformat(object) + "\n") | |
| 107 | ||
| 108 | def pformat(self, object): | |
| 109 | sio = _StringIO() | |
| 110 | self._format(object, sio, 0, 0, {}, 0) | |
| 111 | return sio.getvalue() | |
| 112 | ||
| 113 | def isrecursive(self, object): | |
| 114 | return self.format(object, {}, 0, 0)[2] | |
| 115 | ||
| 116 | def isreadable(self, object): | |
| 117 | s, readable, recursive = self.format(object, {}, 0, 0) | |
| 118 | return readable and not recursive | |
| 119 | ||
| 120 | def _format(self, object, stream, indent, allowance, context, level): | |
| 121 | level = level + 1 | |
| 122 | objid = _id(object) | |
| 123 | if objid in context: | |
| 124 | stream.write(_recursion(object)) | |
| 125 | self._recursive = True | |
| 126 | self._readable = False | |
| 127 | return | |
| 128 | rep = self._repr(object, context, level - 1) | |
| 129 | typ = _type(object) | |
| 130 | sepLines = _len(rep) > (self._width - 1 - indent - allowance) | |
| 131 | write = stream.write | |
| 132 | ||
| 133 | if sepLines: | |
| 134 | r = getattr(typ, "__repr__", None) | |
| 135 | if issubclass(typ, dict) and r is dict.__repr__: | |
| 136 | write('{') | |
| 137 | if self._indent_per_level > 1: | |
| 138 | write((self._indent_per_level - 1) * ' ') | |
| 139 | length = _len(object) | |
| 140 | if length: | |
| 141 | context[objid] = 1 | |
| 142 | indent = indent + self._indent_per_level | |
| 143 | items = object.items() | |
| 144 | items.sort() | |
| 145 | key, ent = items[0] | |
| 146 | rep = self._repr(key, context, level) | |
| 147 | write(rep) | |
| 148 | write(': ') | |
| 149 | self._format(ent, stream, indent + _len(rep) + 2, | |
| 150 | allowance + 1, context, level) | |
| 151 | if length > 1: | |
| 152 | for key, ent in items[1:]: | |
| 153 | rep = self._repr(key, context, level) | |
| 154 | write(',\n%s%s: ' % (' '*indent, rep)) | |
| 155 | self._format(ent, stream, indent + _len(rep) + 2, | |
| 156 | allowance + 1, context, level) | |
| 157 | indent = indent - self._indent_per_level | |
| 158 | del context[objid] | |
| 159 | write('}') | |
| 160 | return | |
| 161 | ||
| 162 | if (issubclass(typ, list) and r is list.__repr__) or \ | |
| 163 | (issubclass(typ, tuple) and r is tuple.__repr__): | |
| 164 | if issubclass(typ, list): | |
| 165 | write('[') | |
| 166 | endchar = ']' | |
| 167 | else: | |
| 168 | write('(') | |
| 169 | endchar = ')' | |
| 170 | if self._indent_per_level > 1: | |
| 171 | write((self._indent_per_level - 1) * ' ') | |
| 172 | length = _len(object) | |
| 173 | if length: | |
| 174 | context[objid] = 1 | |
| 175 | indent = indent + self._indent_per_level | |
| 176 | self._format(object[0], stream, indent, allowance + 1, | |
| 177 | context, level) | |
| 178 | if length > 1: | |
| 179 | for ent in object[1:]: | |
| 180 | write(',\n' + ' '*indent) | |
| 181 | self._format(ent, stream, indent, | |
| 182 | allowance + 1, context, level) | |
| 183 | indent = indent - self._indent_per_level | |
| 184 | del context[objid] | |
| 185 | if issubclass(typ, tuple) and length == 1: | |
| 186 | write(',') | |
| 187 | write(endchar) | |
| 188 | return | |
| 189 | ||
| 190 | write(rep) | |
| 191 | ||
| 192 | def _repr(self, object, context, level): | |
| 193 | repr, readable, recursive = self.format(object, context.copy(), | |
| 194 | self._depth, level) | |
| 195 | if not readable: | |
| 196 | self._readable = False | |
| 197 | if recursive: | |
| 198 | self._recursive = True | |
| 199 | return repr | |
| 200 | ||
| 201 | def format(self, object, context, maxlevels, level): | |
| 202 | """Format object for a specific context, returning a string | |
| 203 | and flags indicating whether the representation is 'readable' | |
| 204 | and whether the object represents a recursive construct. | |
| 205 | """ | |
| 206 | return _safe_repr(object, context, maxlevels, level) | |
| 207 | ||
| 208 | ||
| 209 | # Return triple (repr_string, isreadable, isrecursive). | |
| 210 | ||
| 211 | def _safe_repr(object, context, maxlevels, level): | |
| 212 | typ = _type(object) | |
| 213 | if typ is str: | |
| 214 | if 'locale' not in _sys.modules: | |
| 215 | return repr(object), True, False | |
| 216 | if "'" in object and '"' not in object: | |
| 217 | closure = '"' | |
| 218 | quotes = {'"': '\\"'} | |
| 219 | else: | |
| 220 | closure = "'" | |
| 221 | quotes = {"'": "\\'"} | |
| 222 | qget = quotes.get | |
| 223 | sio = _StringIO() | |
| 224 | write = sio.write | |
| 225 | for char in object: | |
| 226 | if char.isalpha(): | |
| 227 | write(char) | |
| 228 | else: | |
| 229 | write(qget(char, repr(char)[1:-1])) | |
| 230 | return ("%s%s%s" % (closure, sio.getvalue(), closure)), True, False | |
| 231 | ||
| 232 | r = getattr(typ, "__repr__", None) | |
| 233 | if issubclass(typ, dict) and r is dict.__repr__: | |
| 234 | if not object: | |
| 235 | return "{}", True, False | |
| 236 | objid = _id(object) | |
| 237 | if maxlevels and level > maxlevels: | |
| 238 | return "{...}", False, objid in context | |
| 239 | if objid in context: | |
| 240 | return _recursion(object), False, True | |
| 241 | context[objid] = 1 | |
| 242 | readable = True | |
| 243 | recursive = False | |
| 244 | components = [] | |
| 245 | append = components.append | |
| 246 | level += 1 | |
| 247 | saferepr = _safe_repr | |
| 248 | for k, v in object.iteritems(): | |
| 249 | krepr, kreadable, krecur = saferepr(k, context, maxlevels, level) | |
| 250 | vrepr, vreadable, vrecur = saferepr(v, context, maxlevels, level) | |
| 251 | append("%s: %s" % (krepr, vrepr)) | |
| 252 | readable = readable and kreadable and vreadable | |
| 253 | if krecur or vrecur: | |
| 254 | recursive = True | |
| 255 | del context[objid] | |
| 256 | return "{%s}" % _commajoin(components), readable, recursive | |
| 257 | ||
| 258 | if (issubclass(typ, list) and r is list.__repr__) or \ | |
| 259 | (issubclass(typ, tuple) and r is tuple.__repr__): | |
| 260 | if issubclass(typ, list): | |
| 261 | if not object: | |
| 262 | return "[]", True, False | |
| 263 | format = "[%s]" | |
| 264 | elif _len(object) == 1: | |
| 265 | format = "(%s,)" | |
| 266 | else: | |
| 267 | if not object: | |
| 268 | return "()", True, False | |
| 269 | format = "(%s)" | |
| 270 | objid = _id(object) | |
| 271 | if maxlevels and level > maxlevels: | |
| 272 | return format % "...", False, objid in context | |
| 273 | if objid in context: | |
| 274 | return _recursion(object), False, True | |
| 275 | context[objid] = 1 | |
| 276 | readable = True | |
| 277 | recursive = False | |
| 278 | components = [] | |
| 279 | append = components.append | |
| 280 | level += 1 | |
| 281 | for o in object: | |
| 282 | orepr, oreadable, orecur = _safe_repr(o, context, maxlevels, level) | |
| 283 | append(orepr) | |
| 284 | if not oreadable: | |
| 285 | readable = False | |
| 286 | if orecur: | |
| 287 | recursive = True | |
| 288 | del context[objid] | |
| 289 | return format % _commajoin(components), readable, recursive | |
| 290 | ||
| 291 | rep = repr(object) | |
| 292 | return rep, (rep and not rep.startswith('<')), False | |
| 293 | ||
| 294 | ||
| 295 | def _recursion(object): | |
| 296 | return ("<Recursion on %s with id=%s>" | |
| 297 | % (_type(object).__name__, _id(object))) | |
| 298 | ||
| 299 | ||
| 300 | def _perfcheck(object=None): | |
| 301 | import time | |
| 302 | if object is None: | |
| 303 | object = [("string", (1, 2), [3, 4], {5: 6, 7: 8})] * 100000 | |
| 304 | p = PrettyPrinter() | |
| 305 | t1 = time.time() | |
| 306 | _safe_repr(object, {}, None, 0) | |
| 307 | t2 = time.time() | |
| 308 | p.pformat(object) | |
| 309 | t3 = time.time() | |
| 310 | print "_safe_repr:", t2 - t1 | |
| 311 | print "pformat:", t3 - t2 | |
| 312 | ||
| 313 | if __name__ == "__main__": | |
| 314 | _perfcheck() |