getting source line number

[Skaperen]

is there a way to get the source file line number in some code?  for example:

from __future__ import print_function

# print a message with source line number

n = get_source_code_file_line_number()
n += 2
print('now printing at line',str(n))

Output:
now printing at line 6

OR

from __future__ import print_function
for n in range(3)
    print('now printing at line',str(get_source_code_file_line_number()))
    print('now printing at line',str(get_source_code_file_line_number()))

Output:
now printing at line 2
now printing at line 3
now printing at line 2
now printing at line 3
now printing at line 2
now printing at line 3

it's ok if it is based on starting at 1 instead of 0.

[Larz60+]

Many (most?) editors can toggle line numbers off and on.

[Skaperen]

i mean at run time

---

i found this solution that seems to work:

import inspect
print( 'line', inspect.getframeinfo(inspect.currentframe()).lineno, 'of file', inspect.getframeinfo(inspect.currentframe()).filename )

[snippsat]

Yes can use inspect for this.
Can make a function,then insert that function call will print line number.

import inspect

def line_numb():
   '''Returns the current line number in our program'''
   return inspect.currentframe().f_back.f_lineno

# print a message with source line number
n = 2 ; print('variable {} is at line {}'.format(n, line_numb()))
print('now printing at line {}'.format(line_numb()))

Output:
variable 2 is at line 8
now printing at line 9

[Skaperen]

Yes can use inspect for this.
Can make a function,then insert that function call will print line number.

import inspect

def line_numb():
   '''Returns the current line number in our program'''
   return inspect.currentframe().f_back.f_lineno

# print a message with source line number
n = 2 ; print('variable {} is at line {}'.format(n, line_numb()))
print('now printing at line {}'.format(line_numb()))

Output:
variable 2 is at line 8
now printing at line 9

this also gives me the solution to another long time problem: a function to display the name and value of a variable, given only one argument ... a string of the name (so a coding error by the user of this function cannot result in a mismatch)

from inspect import currentframe
from os import environ
def v(n):
    if 'nodebug' in environ:
        return
    x=currentframe().f_back.f_locals
    if n not in x:
        return print(n,'not assigned')
    return print(n,'=',repr(x[n]))

(*) code not tested

edit: correction applied to code: s/[0]//