Lib/traceback.py

   1 # Format and print Python stack traces
   2
   3 import linecache
   4 import string
   5 import sys
   6 import types
   7
   8 def _print(file, str='', terminator='\n'):
   9         file.write(str+terminator)
  10
  11
  12 def print_tb(tb, limit=None, file=None):
  13         if not file:
  14                 file = sys.stderr
  15         if limit is None:
  16                 if hasattr(sys, 'tracebacklimit'):
  17                         limit = sys.tracebacklimit
  18         n = 0
  19         while tb is not None and (limit is None or n < limit):
  20                 f = tb.tb_frame
  21                 lineno = tb.tb_lineno
  22                 co = f.f_code
  23                 filename = co.co_filename
  24                 name = co.co_name
  25                 _print(file,
  26                        '  File "%s", line %d, in %s' % (filename,lineno,name))
  27                 line = linecache.getline(filename, lineno)
  28                 if line: _print(file, '    ' + string.strip(line))
  29                 tb = tb.tb_next
  30                 n = n+1
  31
  32 def format_tb(tb, limit = None):
  33         list = []
  34         for filename, lineno, name, line in extract_tb(tb, limit):
  35                 item = '  File "%s", line %d, in %s\n' % (filename,lineno,name)
  36                 if line:
  37                         item = item + '    %s\n' % string.strip(line)
  38                 list.append(item)
  39         return list
  40
  41 def extract_tb(tb, limit = None):
  42         if limit is None:
  43                 if hasattr(sys, 'tracebacklimit'):
  44                         limit = sys.tracebacklimit
  45         list = []
  46         n = 0
  47         while tb is not None and (limit is None or n < limit):
  48                 f = tb.tb_frame
  49                 lineno = tb.tb_lineno
  50                 co = f.f_code
  51                 filename = co.co_filename
  52                 name = co.co_name
  53                 line = linecache.getline(filename, lineno)
  54                 if line: line = string.strip(line)
  55                 else: line = None
  56                 list.append(filename, lineno, name, line)
  57                 tb = tb.tb_next
  58                 n = n+1
  59         return list
  60
  61
  62 def print_exception(etype, value, tb, limit=None, file=None):
  63         if not file:
  64                 file = sys.stderr
  65         if tb:
  66                 _print(file, 'Traceback (innermost last):')
  67                 print_tb(tb, limit, file)
  68         lines = format_exception_only(etype, value)
  69         for line in lines[:-1]:
  70                 _print(file, line, ' ')
  71         _print(file, lines[-1], '')
  72
  73 def format_exception(etype, value, tb, limit = None):
  74         if tb:
  75                 list = ['Traceback (innermost last):\n']
  76                 list = list + format_tb(tb, limit)
  77         list = list + format_exception_only(etype, value)
  78         return list
  79
  80 def format_exception_only(etype, value):
  81         list = []
  82         if type(etype) == types.ClassType:
  83                 stype = etype.__name__
  84         else:
  85                 stype = etype
  86         if value is None:
  87                 list.append(str(stype) + '\n')
  88         else:
  89                 if etype is SyntaxError:
  90                         try:
  91                                 msg, (filename, lineno, offset, line) = value
  92                         except:
  93                                 pass
  94                         else:
  95                                 if not filename: filename = "<string>"
  96                                 list.append('  File "%s", line %d\n' %
  97                                             (filename, lineno))
  98                                 i = 0
  99                                 while i < len(line) and \
 100                                       line[i] in string.whitespace:
 101                                         i = i+1
 102                                 list.append('    %s\n' % string.strip(line))
 103                                 s = '    '
 104                                 for c in line[i:offset-1]:
 105                                         if c in string.whitespace:
 106                                                 s = s + c
 107                                         else:
 108                                                 s = s + ' '
 109                                 list.append('%s^\n' % s)
 110                                 value = msg
 111                 list.append('%s: %s\n' % (str(stype), str(value)))
 112         return list
 113
 114
 115 def print_exc(limit=None, file=None):
 116         if not file:
 117                 file = sys.stderr
 118         print_exception(sys.exc_type, sys.exc_value, sys.exc_traceback,
 119                         limit, file)
 120
 121 def print_last(limit=None, file=None):
 122         if not file:
 123                 file = sys.stderr
 124         print_exception(sys.last_type, sys.last_value, sys.last_traceback,
 125                         limit, file)