source file: /System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/traceback.py
file stats: 165 lines, 4 executed: 2.4% covered
1. """Extract, format and print information about Python stack traces.""" 2. 3. import linecache 4. import sys 5. import types 6. 7. __all__ = ['extract_stack', 'extract_tb', 'format_exception', 8. 'format_exception_only', 'format_list', 'format_stack', 9. 'format_tb', 'print_exc', 'print_exception', 'print_last', 10. 'print_stack', 'print_tb', 'tb_lineno'] 11. 12. def _print(file, str='', terminator='\n'): 13. file.write(str+terminator) 14. 15. 16. def print_list(extracted_list, file=None): 17. """Print the list of tuples as returned by extract_tb() or 18. extract_stack() as a formatted stack trace to the given file.""" 19. if file is None: 20. file = sys.stderr 21. for filename, lineno, name, line in extracted_list: 22. _print(file, 23. ' File "%s", line %d, in %s' % (filename,lineno,name)) 24. if line: 25. _print(file, ' %s' % line.strip()) 26. 27. def format_list(extracted_list): 28. """Format a list of traceback entry tuples for printing. 29. 30. Given a list of tuples as returned by extract_tb() or 31. extract_stack(), return a list of strings ready for printing. 32. Each string in the resulting list corresponds to the item with the 33. same index in the argument list. Each string ends in a newline; 34. the strings may contain internal newlines as well, for those items 35. whose source text line is not None. 36. """ 37. list = [] 38. for filename, lineno, name, line in extracted_list: 39. item = ' File "%s", line %d, in %s\n' % (filename,lineno,name) 40. if line: 41. item = item + ' %s\n' % line.strip() 42. list.append(item) 43. return list 44. 45. 46. def print_tb(tb, limit=None, file=None): 47. """Print up to 'limit' stack trace entries from the traceback 'tb'. 48. 49. If 'limit' is omitted or None, all entries are printed. If 'file' 50. is omitted or None, the output goes to sys.stderr; otherwise 51. 'file' should be an open file or file-like object with a write() 52. method. 53. """ 54. if file is None: 55. file = sys.stderr 56. if limit is None: 57. if hasattr(sys, 'tracebacklimit'): 58. limit = sys.tracebacklimit 59. n = 0 60. while tb is not None and (limit is None or n < limit): 61. f = tb.tb_frame 62. lineno = tb.tb_lineno 63. co = f.f_code 64. filename = co.co_filename 65. name = co.co_name 66. _print(file, 67. ' File "%s", line %d, in %s' % (filename,lineno,name)) 68. line = linecache.getline(filename, lineno) 69. if line: _print(file, ' ' + line.strip()) 70. tb = tb.tb_next 71. n = n+1 72. 73. def format_tb(tb, limit = None): 74. """A shorthand for 'format_list(extract_stack(f, limit)).""" 75. return format_list(extract_tb(tb, limit)) 76. 77. def extract_tb(tb, limit = None): 78. """Return list of up to limit pre-processed entries from traceback. 79. 80. This is useful for alternate formatting of stack traces. If 81. 'limit' is omitted or None, all entries are extracted. A 82. pre-processed stack trace entry is a quadruple (filename, line 83. number, function name, text) representing the information that is 84. usually printed for a stack trace. The text is a string with 85. leading and trailing whitespace stripped; if the source is not 86. available it is None. 87. """ 88. if limit is None: 89. if hasattr(sys, 'tracebacklimit'): 90. limit = sys.tracebacklimit 91. list = [] 92. n = 0 93. while tb is not None and (limit is None or n < limit): 94. f = tb.tb_frame 95. lineno = tb.tb_lineno 96. co = f.f_code 97. filename = co.co_filename 98. name = co.co_name 99. line = linecache.getline(filename, lineno) 100. if line: line = line.strip() 101. else: line = None 102. list.append((filename, lineno, name, line)) 103. tb = tb.tb_next 104. n = n+1 105. return list 106. 107. 108. def print_exception(etype, value, tb, limit=None, file=None): 109. """Print exception up to 'limit' stack trace entries from 'tb' to 'file'. 110. 111. This differs from print_tb() in the following ways: (1) if 112. traceback is not None, it prints a header "Traceback (most recent 113. call last):"; (2) it prints the exception type and value after the 114. stack trace; (3) if type is SyntaxError and value has the 115. appropriate format, it prints the line where the syntax error 116. occurred with a caret on the next line indicating the approximate 117. position of the error. 118. """ 119. if file is None: 120. file = sys.stderr 121. if tb: 122. _print(file, 'Traceback (most recent call last):') 123. print_tb(tb, limit, file) 124. lines = format_exception_only(etype, value) 125. for line in lines[:-1]: 126. _print(file, line, ' ') 127. _print(file, lines[-1], '') 128. 129. def format_exception(etype, value, tb, limit = None): 130. """Format a stack trace and the exception information. 131. 132. The arguments have the same meaning as the corresponding arguments 133. to print_exception(). The return value is a list of strings, each 134. ending in a newline and some containing internal newlines. When 135. these lines are concatenated and printed, exactly the same text is 136. printed as does print_exception(). 137. """ 138. if tb: 139. list = ['Traceback (most recent call last):\n'] 140. list = list + format_tb(tb, limit) 141. else: 142. list = [] 143. list = list + format_exception_only(etype, value) 144. return list 145. 146. def format_exception_only(etype, value): 147. """Format the exception part of a traceback. 148. 149. The arguments are the exception type and value such as given by 150. sys.last_type and sys.last_value. The return value is a list of 151. strings, each ending in a newline. Normally, the list contains a 152. single string; however, for SyntaxError exceptions, it contains 153. several lines that (when printed) display detailed information 154. about where the syntax error occurred. The message indicating 155. which exception occurred is the always last string in the list. 156. """ 157. list = [] 158. if type(etype) == types.ClassType: 159. stype = etype.__name__ 160. else: 161. stype = etype 162. if value is None: 163. list.append(str(stype) + '\n') 164. else: 165. if etype is SyntaxError: 166. try: 167. msg, (filename, lineno, offset, line) = value 168. except: 169. pass 170. else: 171. if not filename: filename = "<string>" 172. list.append(' File "%s", line %d\n' % 173. (filename, lineno)) 174. if line is not None: 175. i = 0 176. while i < len(line) and line[i].isspace(): 177. i = i+1 178. list.append(' %s\n' % line.strip()) 179. if offset is not None: 180. s = ' ' 181. for c in line[i:offset-1]: 182. if c.isspace(): 183. s = s + c 184. else: 185. s = s + ' ' 186. list.append('%s^\n' % s) 187. value = msg 188. s = _some_str(value) 189. if s: 190. list.append('%s: %s\n' % (str(stype), s)) 191. else: 192. list.append('%s\n' % str(stype)) 193. return list 194. 195. def _some_str(value): 196. try: 197. return str(value) 198. except: 199. return '<unprintable %s object>' % type(value).__name__ 200. 201. 202. def print_exc(limit=None, file=None): 203. """Shorthand for 'print_exception(sys.exc_type, sys.exc_value, sys.exc_traceback, limit, file)'. 204. (In fact, it uses sys.exc_info() to retrieve the same information 205. in a thread-safe way.)""" 206. if file is None: 207. file = sys.stderr 208. try: 209. etype, value, tb = sys.exc_info() 210. print_exception(etype, value, tb, limit, file) 211. finally: 212. etype = value = tb = None 213. 214. def print_last(limit=None, file=None): 215. """This is a shorthand for 'print_exception(sys.last_type, 216. sys.last_value, sys.last_traceback, limit, file)'.""" 217. if file is None: 218. file = sys.stderr 219. print_exception(sys.last_type, sys.last_value, sys.last_traceback, 220. limit, file) 221. 222. 223. def print_stack(f=None, limit=None, file=None): 224. """Print a stack trace from its invocation point. 225. 226. The optional 'f' argument can be used to specify an alternate 227. stack frame at which to start. The optional 'limit' and 'file' 228. arguments have the same meaning as for print_exception(). 229. """ 230. if f is None: 231. try: 232. raise ZeroDivisionError 233. except ZeroDivisionError: 234. f = sys.exc_info()[2].tb_frame.f_back 235. print_list(extract_stack(f, limit), file) 236. 237. def format_stack(f=None, limit=None): 238. """Shorthand for 'format_list(extract_stack(f, limit))'.""" 239. if f is None: 240. try: 241. raise ZeroDivisionError 242. except ZeroDivisionError: 243. f = sys.exc_info()[2].tb_frame.f_back 244. return format_list(extract_stack(f, limit)) 245. 246. def extract_stack(f=None, limit = None): 247. """Extract the raw traceback from the current stack frame. 248. 249. The return value has the same format as for extract_tb(). The 250. optional 'f' and 'limit' arguments have the same meaning as for 251. print_stack(). Each item in the list is a quadruple (filename, 252. line number, function name, text), and the entries are in order 253. from oldest to newest stack frame. 254. """ 255. if f is None: 256. try: 257. raise ZeroDivisionError 258. except ZeroDivisionError: 259. f = sys.exc_info()[2].tb_frame.f_back 260. if limit is None: 261. if hasattr(sys, 'tracebacklimit'): 262. limit = sys.tracebacklimit 263. list = [] 264. n = 0 265. while f is not None and (limit is None or n < limit): 266. lineno = f.f_lineno 267. co = f.f_code 268. filename = co.co_filename 269. name = co.co_name 270. line = linecache.getline(filename, lineno) 271. if line: line = line.strip() 272. else: line = None 273. list.append((filename, lineno, name, line)) 274. f = f.f_back 275. n = n+1 276. list.reverse() 277. return list 278. 279. def tb_lineno(tb): 280. """Calculate correct line number of traceback given in tb. 281. 282. Obsolete in 2.3. 283. """ 284. return tb.tb_lineno