Thanks @tleonhardt, let me try with the latest & check.

Below is the information you had requested:
cmd2 version: cmd2 2.4.3
Python version: Python 3.6.8
I am using linux:

$ cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.8 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.8 (Ootpa)"

$ lscpu | head -n 5
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15

Terminal program: iterm2 only

Due to some confidentiality agreements, unable to disclose exact information on the cmd2 app, but it is initialized like this:

 # cmd2 initialization
 super().__init__(
 persistent_history_file=settings.get_system_default('persistent_history_file'),
 persistent_history_length=settings.get_system_default('persistent_history_length'),
 startup_script=settings.get_system_default('shell_startup_script'),
 include_py=True,
 allow_redirection=True,
 terminators=[],
 shortcuts=settings.get_system_default('shell_shortcuts')
 )
 # Set necessary cmd2 instance variables
 self.self_in_py = True
 self.max_completion_items = settings.get_system_default('shell_max_completion_items')
 self.hidden_commands.append('quit')
 self.remove_settable('allow_style')
 self.remove_settable('always_show_hint')
 self.remove_settable('echo')
 self.remove_settable('editor')
 self.remove_settable('feedback_to_output')
 self.remove_settable('max_completion_items')
 self.remove_settable('quiet')
 self.remove_settable('timing')

I use read_input a lot, so might be related with that as well especially when the command quits after using it:

def do_xxx(self, args):
 input = self.read_input('Input:')
 return

I would face noticeable delays when using commands like 'xxx' which uses read_input.

Please let me know if you need any more information.
Sorry about the confidentiality part, but i can guarantee it's not for long. Once the app gets open-sourced after development, i will definitely share it with you guys!

@Sripadvallabh It's always fascinating for me to see the myriad ways in which people use cmd2 which end up being so very different than I ever envisioned!

Personally, I've never used self.read_input() within a command. I always use the @cmd2.with_argparser decorator to define command arguments using argparse that can get nicely validated when the command is called so that all required input for a command is provided up front.

I think @kmvanbrunt might have more experience using read_input() within a command and might be able to more intelligently comment about why that might impact performance.

I noticed you are using a version of Python which hit end-of-life (EOL) several years ago and similarly outdated version of cmd2. I have no idea what your constraints are, but if you could upgrade to a newer version of Python and cmd2, it would likely be a good thing. Unfortunately, the version of cmd2 you are using is the last one that works with Python 3.6.

Actually, @tleonhardt my use-case was a pretty different one. I needed a prompt within a command to get multiple inputs from user & need to return back a response for each of them since the command was to be designed that way as each inputs get tied together to the previous input so a chain of inputs was necessary. I asked users to use '+' within the cmd2 command itself to separate them, but we missed the response for each of the individual input. Hence, the current design. I also needed autocompletion & argparse functionality so i opted to use the easy read_input provided by cmd2. It is far better than prompt_toolkit or other packages as it's easy to use, no need to do another extra import & only needs a setup with the Cmd2ArgumentParser().

Sorry, i noticed i put a wrong version of python above. My actual python version is: Python 3.8.2.

Thanks for addressing the issue posted. Actually i am using cmd2 2.5.4 & i have applied a patch for now to make it work. I am yet to migrate to 3.0.0.