Description

artemmukhin

opened on Apr 6, 2023

Issue body actions

Bug report

Run the following program

import inspect
import inspect
_, lineno1 = inspect.getsourcelines(inspect.currentframe())
_, lineno2 = inspect.findsource(inspect.currentframe())
print(lineno1, lineno2)

Expected Result
The line numbers are expected to be 1-based, so the expected output is 1 1.

Actual Result
The actual output is 0 0.

Related discussion: #103226

Your environment

• CPython versions tested on: main branch
• Operating system and architecture: macOS

Linked PRs

• GH-103319: Fix inspect.getsourcelines() to return 1-based line numbers #103226

Activity

1. artemmukhin

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Apr 6, 2023
2. artemmukhin

   changed the title [-]`inspect.getsourcelines` returns 0 as the starting line number for modules[/-] [+]`inspect.{getsourcelines, findsource}` return 0 as the starting line number for modules[/+] on Apr 6, 2023
3. AlexWaygood

   added

   stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

   on Apr 6, 2023
4. serhiy-storchaka

   added this to Inspect issues 🔍on Mar 5, 2024
5. George-Ogden commented on Jul 20, 2025

   

   George-Ogden

   on Jul 20, 2025

   Contributor

   More actions

   inspect.getsourcelines(frame) seems to return the 1-based index or 0 (when the whole file is returned).

   Here are some examples:

   frame = inspect.currentframe()
   inspect.getsourcelines(frame) # _, 0

   def foo(): # start of file
       import inspect
       frame = inspect.currentframe()
       inspect.getsourcelines(frame) # _, 1
   
   foo()

   import inspect
   
   ...
   
   def bar():
       frame = inspect.currentframe()
       inspect.getsourcelines(frame) # _, n (1-based index)
   
   bar()

   Currently, I work around this with:

   source, offset = inspect.getsourcelines(frame)
   offset = max(1, offset)

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