You're looking for calls to sys.exit(...) (exit(...) calls sys.exit(...)) in the script. The argument to that method is returned to the environment as the exit code.
It's fairly likely that the script is never calling the exit(...) method, and that 0 is the default exit code.
You're looking for calls to sys.exit(...) (exit(...) calls sys.exit(...)) in the script. The argument to that method is returned to the environment as the exit code.
It's fairly likely that the script is never calling the exit(...) method, and that 0 is the default exit code.
From the documentation for sys.exit:
The optional argument arg can be an integer giving the exit status (defaulting to zero), or another type of object. If it is an integer, zero is considered “successful termination” and any nonzero value is considered “abnormal termination” by shells and the like. Most systems require it to be in the range 0-127, and produce undefined results otherwise. Some systems have a convention for assigning specific meanings to specific exit codes, but these are generally underdeveloped; Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors.
One example where exit codes are used are in shell scripts. In Bash you can check the special variable $? for the last exit status:
me@mini:~$ python -c ""; echo $?
0
me@mini:~$ python -c "import sys; sys.exit(0)"; echo $?
0
me@mini:~$ python -c "import sys; sys.exit(43)"; echo $?
43
Personally I try to use the exit codes I find in /usr/include/asm-generic/errno.h (on a Linux system), but I don't know if this is the right thing to do.
Python always displaying exit code 0
python - How do I terminate a script? - Stack Overflow
Terminate code
The Python process failed (exit code: 2)
Videos
Hi, so i'm mostly new to coding and i have an initial test for a course this sunday. I'm using Python for it and what i wanna ask is, why does the "Process finished with exit code 0" message get displayed when there are certainly lots of issues with the code that even i as a noob can see? It often also comes without an output. I can place a single example, but it happens damn near every time.
import sys
sys.exit()
This will exit with status code 0; if you don't want that, you can pass a different one or a message:
sys.exit(1)
details from the sys module documentation:
sys.exit([arg])Exit from Python. This is implemented by raising the
SystemExitexception, so cleanup actions specified by finally clauses oftrystatements are honored, and it is possible to intercept the exit attempt at an outer level.The optional argument arg can be an integer giving the exit status (defaulting to zero), or another type of object. If it is an integer, zero is considered “successful termination” and any nonzero value is considered “abnormal termination” by shells and the like. Most systems require it to be in the range 0-127, and produce undefined results otherwise. Some systems have a convention for assigning specific meanings to specific exit codes, but these are generally underdeveloped; Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors. If another type of object is passed, None is equivalent to passing zero, and any other object is printed to
stderrand results in an exit code of 1. In particular,sys.exit("some error message")is a quick way to exit a program when an error occurs.Since
exit()ultimately “only” raises an exception, it will only exit the process when called from the main thread, and the exception is not intercepted.
Note that this is the 'nice' way to exit. @glyphtwistedmatrix below points out that if you want a 'hard exit', you can use os._exit(*errorcode*), though it's likely os-specific to some extent (it might not take an errorcode under windows, for example), and it definitely is less friendly since it doesn't let the interpreter do any cleanup before the process dies. On the other hand, it does kill the entire process, including all running threads, while sys.exit() (as it says in the docs) only exits if called from the main thread, with no other threads running.
A simple way to terminate a Python script early is to use the built-in quit() function. There is no need to import any library, and it is efficient and simple.
Example:
#do stuff
if this == that:
quit()
However, this relies on an implicit import of the site module. Per the docs:
The site module (which is imported automatically during startup, except if the -S command-line option is given) adds several constants to the built-in namespace. They are useful for the interactive interpreter shell and should not be used in programs.
As such, if the -S flag is passed, this may raise a NameError with the message "name 'quit' is not defined".
Hey, how can we end a program without using break, exit or quit functions. Like just using if statement how can I terminate a program?