I used to have an older version of python 2.7 that has worked for years. I just upgraded to 2.7.13 for Windows, 32 bit and now, I can't get the interpreter to run from the command line. It just returns to the DOS prompt.

c:\Python27>python
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
c:\Python27>python

PC:
OS: Windows 7 - 64 bit (I am intentionally using the 32bit of python)
Processor: AMD PhenomII 975 Processor. 3.6GHz
RAM: 16GB

Although I don't remember seeing a crash out as quick as this, common 
causes for this kind of thing are to do with environment variables 
pointing to still-existing or part-existing installations. Can you try:

set PY

from a command prompt, please, to see if any Python-related env vars are 
present. (Typically PYTHONHOME is the culprit)

Readline is also a common culprit when it's crashing out at the interactive prompt. Try either uninstalling or upgrading any packages that may include a readline module.

c:\Python27>SET PY
Environment variable PY not defined


I don't know anything about readline or how to find what uses it.

To get more information during the Python initialization, you can try to run:

python -X faulthandler -S -v

* -X faulthandler: dump a traceback if python crashed (is it the case? I don't understand from the bug report)
* -S disables the site module
* -v enables verbose mode

It doesn't appear to be a crash, but seems like the REPL is quitting because there's no input (e.g. like stdin is redirected to NUL). Echo %errorlevel%; it's probably 0. 

readline (pyreadline) is probably the culprit. Try the following shell commands to temporarily disable it:

    ren C:\Python27\Lib\site-packages\readline.py readline.py.bak
    del C:\Python27\Lib\site-packages\readline.pyc

If it's not installed, then these commands will fail.

Excellent analysis guys! Thank you!

The -X faulthandler option didn't work.
The -S -v, however, did. 
Finally, renaming and deleting the readline entries fixed it such that I can now launch the REPL. 
Question. What does " disables the site module" for the -S option mean?

Now, what do I do about the (py)readline issue? Do I need to reinstall something?

Logs below:


c:\Python27>python
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.

c:\Python27>python -X faulthandler -S -v
-X is reserved for implementation-specific arguments
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

c:\Python27>python -X
-X is reserved for implementation-specific arguments
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

c:\Python27>python -X -faulthandler -S -v
-X is reserved for implementation-specific arguments
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

c:\Python27>python  -S -v
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)] on win32
>>> ^Z

# clear __builtin__._
# clear sys.path
# clear sys.argv
# clear sys.ps1
# clear sys.ps2
# clear sys.exitfunc
# clear sys.exc_type
# clear sys.exc_value
# clear sys.exc_traceback
# clear sys.last_type
# clear sys.last_value
# clear sys.last_traceback
# clear sys.path_hooks
# clear sys.path_importer_cache
# clear sys.meta_path
# clear sys.flags
# clear sys.float_info
# restore sys.stdin
# restore sys.stdout
# restore sys.stderr
# cleanup __main__
# cleanup[1] zipimport
# cleanup[1] signal
# cleanup[1] exceptions
# cleanup[1] _warnings
# cleanup sys
# cleanup __builtin__
# cleanup ints: 6 unfreed ints
# cleanup floats

c:\Python27>python
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.

c:\Python27>ren C:\Python27\Lib\site-packages\readline.py readline.py.bak

c:\Python27>del C:\Python27\Lib\site-packages\readline.pyc

c:\Python27>python
Python 2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

You should be able to update whatever package installed that module. Unfortunately, we can't guess what that would be, but it's probably worthwhile updating all the packages you have installed.