The behavior is consistent with running those commands with python3. Do you see a difference?

Well, python3 never prints the banner when using -c.

Also, python3 doesn't uses ncurses, so a comparison is not really possible.

Since bpython uses ncurses, it should do so in all interactive cases, including bpython -i -c 'from mymodule import *', no?

Well, python3 never prints the banner when using -c.

In which case does bpython print a banner when using -c?

Also, python3 doesn't uses ncurses, so a comparison is not really possible.

The goal is that the common command line options behave the same. If they don't, that's a bug. If they are consistent with python3, it's not.

The goal is that the common command line options behave the same. If they don't, that's a bug. If they are consistent with python3, it's not.

Then perhaps a new command line switch (which injects an initial command into the interactive session) would be best.

For the record: both bpython -i file.py and setting PYTHONSTARTUP=/path/to/file.py would work, but for a short simple oneliner, having to create a file is not that convenient. That probably is also the reason of having a -c command line switch in python, although that could be intended for different usecases than interactive sessions.

A similar option exists called --paste that reads from a file. I see, you'd like this from the command line.

--paste pastes from file. In this scenario it doesn't add anything to -i (see above).

Pasting from a string would make sense.

If I have gone thru the effort of putting my from mymodule import * line into a file, then also bpython -i file.py would work, as I already said above; or the same work can be off-loaded to the shell (YMMV), e.g. with zsh, there are two ways.

1. process substitution, but bpython won't work with a fd:

❯ bpython -p <(echo 'from mymodule import *')
bpython version 0.24 on top of Python 3.11.4 /opt/homebrew/opt/python@3.11/bin/python3.11

Traceback (most recent call last):
  File "/opt/homebrew/bin/bpython", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/bpython/curtsies.py", line 248, in main
    repl.mainloop(True, paste)
  File "/opt/homebrew/lib/python3.11/site-packages/bpython/curtsies.py", line 170, in mainloop
    self.process_event(paste)
  File "/opt/homebrew/lib/python3.11/site-packages/bpython/curtsiesfrontend/repl.py", line 656, in process_event
    return self.process_control_event(e)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/bpython/curtsiesfrontend/repl.py", line 681, in process_control_event
    ctrl_char = compress_paste_event(e)
                ^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/bpython/curtsiesfrontend/repl.py", line 2228, in compress_paste_event
    event = paste_event.events[0]
            ~~~~~~~~~~~~~~~~~~^^^
IndexError: list index out of range

2. temp file substitution:

❯ bpython -p =(echo 'from mymodule import *')
bpython version 0.24 on top of Python 3.11.4 /opt/homebrew/opt/python@3.11/bin/python3.11
>>> from mymodule import *
>>>

The second form works, but it creates a temp file, so I somewhat still dislike that (I think as a temp file as the very last resort workaround, the apotheosis of failed integration between two programs).

Reading from a fd (named pipe) <(echo 'from mymodule import *') would be slightly better, but the best I think is supporting also an actual string to paste.

Also, --paste - would not work (in most command line programs, passing - where an input file is expected, means "use stdin"), so it is not possible to use echo 'from mymodule import *' | bpython -p - or bpython -p - <<<'from mymodule import *', but maybe stdin cannot be used like that if we want an interactive session.