Question

When error occured Python prints something like this:

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "<stdin>", line 8, in m
  File "<stdin>", line 5, in exec_st
  File "<stdin>", line 9, in exec_assign
  File "<stdin>", line 48, in ref_by_id
IndexError: list index out of range

where 2, … , 48 are relative line numbers which are not very convenient. How to print absolute line numbers in such error messages?

EDIT:
Maybe it’s a dumb question, but answer will facilitate development a little.
I’m printing text in several files. When done, press shortcut which runs python and copies contents of current file to console. Proposed solution forces to press excess keystrokes (Ctrl+S, Alt+Tab) and create additional files. I hope I have put it clear.

Answer 1

A few minutes of hacking around gives me this Read-Eval-Print Loop in Python 2.7:

#!/usr/bin/env python
import code
import sys

LINE_NUMBER=0

def reset_linenum():
    global LINE_NUMBER
    LINE_NUMBER=-1

def resettable_REPL():
    global LINE_NUMBER
    BUFFERED_LINES=[]
    ii=code.InteractiveInterpreter({"reset_linenum":reset_linenum})
    while True:
        try:
            BUFFERED_LINES.append(raw_input("!"+sys.ps1)+'\n')
            while (BUFFERED_LINES[-1][:1] in " \t" or
                   ii.runsource("\n"*LINE_NUMBER+"".join(BUFFERED_LINES), "console")):
                BUFFERED_LINES.append(raw_input("!"+sys.ps2)+'\n')
            LINE_NUMBER+=len(BUFFERED_LINES)
            BUFFERED_LINES=[]
        except EOFError:
            break

if __name__=='__main__':
    resettable_REPL()

It’s a bit hackish, but it keeps track of line numbers as the session continues, and allows the current count to be reset by a call to reset_linenum(). An example session:

!!!> print "hello"              # line 1
hello
!!!> def badfunc():             # line 2
!...     raise Exception("doh") # line 3
!!!> badfunc()                  # line 4
Traceback (most recent call last):
  File "console", line 4, in <module>
  File "console", line 3, in badfunc
Exception: doh
!!!> ?                          # line 5
  File "console", line 5
    ?
    ^
SyntaxError: invalid syntax
!!!> reset_linenum()            # RESET
!!!> raise Exception("!")       # line 1
Traceback (most recent call last):
  File "console", line 1, in <module>
Exception: !
!!!> 

EDIT: Fixed REPL to not execute indented blocks quite so prematurely.