user8110853 user8110853 -4 years ago 97
Python Question

Can execute python code inside vim with screen but not without. Why?

So, I wanted to be able to execute my python code within Vim so I went here: Running Python code in Vim and found the answer. I mainly try to work work within GNU Screen and that was the way I was working when I added the following code to my .vimrc:

nnoremap <buffer> <F9> :exec '!python' shellescape(@%, 1)<cr>
This line in my .vimrc works great within Vim via GNU Screen, but I'd like to also have it work without using Screen, which is my issue.

For example, if I run a simple Python program

greeting = "Hello"
print (greeting)
name = input("Please enter your name: ")
print(greeting + " " + name)


and press F9, it exits Vim and prompts me at the terminal. In Screen, it prompts me in the buffer (at the bottom of Vim), which is the desired behavior. Anyone have this issue or would know how to fix this?

Here is my .vimrc (and .bashrc) file, the line of code is on line 43. I have it set for python3 but it exihibits the same behavior, regardless of the version of Python I have it set to.

vimrc

" use visual bell instead of beeping
"set vb
"
" Basics {
set nocompatible " explicitly get out of vi-compatible mode
" i added this for colorshemes
"set term=xterm-256color

if $COLORTERM == 'gnome-terminal'
set t_Co=256
endif

syntax on
syntax enable
set background=dark

"let g:two_firewatch_italics=1 "firewatch
"colo two-firewatch "firewatch

" General {
filetype plugin indent on " load filetype plugins/indent settings
set autochdir " always switch to the current file directory
set backspace=indent,eol,start " make backspace a more flexible
set fileformats=unix,dos,mac " support all three, in this order
set iskeyword+=_,$,@,%,# " none of these are word dividers
set mouse=a " use mouse everywhere
set whichwrap=b,s,h,l,<,>,~,[,] " everything wraps
set wildmenu " turn on command line completion wild style

" Vim UI {
set laststatus=2 " always show the status line
set linespace=0 " don't insert any extra pixel lines betweens rows
set matchtime=5 " how many tenths of a second to blink matching brackets for
set novisualbell " don't blink
set number " turn on line numbers
set ruler " Always show current positions along the bottom
set showcmd " show the command being typed
set showmatch " show matching brackets
set statusline=%F%m%r%h%w[%L][%{&ff}]%y[%p%%][%04l,%04v]
nnoremap <C-N> :next<Enter> " this replaces :next, when opening multiple files
nnoremap <C-P> :prev<Enter> " this replaces :prev, when opening multiple files

nnoremap <buffer> <F9> :exec '!python3' shellescape(@%, 1)<cr>
set confirm

" Text Formatting/Layout {
set tabstop=4
set expandtab
set shiftwidth=4 " not sure what this does?
set smarttab autoindent
set softtabstop=4 " when hitting tab or backspace, how many spaces


" paste mode - this will avoid unexpected effects when you
" cut or copy some text from one window and paste it in Vim.
set pastetoggle=<F2>

" The 3 commands below are an experiment
" save file (ctrl-s)
" :map <C-s> :w<cr>
" copy selected text (ctrl-c)
" :vmap <C-c> y
" Paste clipboard contents (ctrl-v)
" :imap <C-p> <esc>P
" Press i to enter insert mode, and ii to exit.
:imap jj <Esc>
:inoremap <C-S> <C-O>:w<CR>


" Filetype-Dependent Settings
filetype plugin on
filetype indent on

set modifiable

" Pathogen related
execute pathogen#infect()
call pathogen#helptags()
syntax on
filetype plugin indent on

"colorscheme molokai
highlight Comment cterm=bold

if &term =~ '256color'
" disable Background Color Erase (BCE) so that color schemes
" render properly when inside 256-color tmux and GNU screen.
" see also http://snk.tuxfamily.org/log/vim-256color-bce.html
set t_ut=
endif


bashrc

# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples
export TERM=xterm-256color
# If not running interactively, don't do anything
case $- in
*i*) ;;
*) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
xterm-color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
# We have color support; assume it's compliant with Ecma-48
# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
# a case would tend to support setf rather than setaf.)
color_prompt=yes
else
color_prompt=
fi
fi

if [ "$color_prompt" = yes ]; then
PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
;;
*)
;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
alias ls='ls --color=auto'
#alias dir='dir --color=auto'
#alias vdir='vdir --color=auto'

alias grep='grep --color=auto'
alias fgrep='fgrep --color=auto'
alias egrep='egrep --color=auto'
fi

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands. Use like so:
# sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
if [ -f /usr/share/bash-completion/bash_completion ]; then
. /usr/share/bash-completion/bash_completion
elif [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
fi

export NVM_DIR="/home/serge/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm

Answer Source

If you run anything from vim using :exec it is always on the terminal. Simplifying things a little it goes more or less like: when you spawn a command from vim, it switches to the terminal and calling terminal init sequence. What exactly the terminal init sequence means is encoded in terminal definition. For example, for xterm it means switch to buffer used previously and set the cursor in the last known position on this buffer. For screen it means: move cursor to the bottom line of the screen. That's why it gives you appearance of vim buffer. BTW, for other kind of terminal it could be clean the screen and move cursor to the top line. As I told - it's simplification. If you are interested about technical details, ncurses is the topic to read about.

So, in summary, vim always ask a terminal to do the same sequence of terminal command. If given command is known and executed by terminal, it depends on the terminal.

If you want to run something to get results inside vim buffer, you need to write a plugin to create a buffer and make it possible to interact between your command and a buffer. I wouldn't be surprised if someone have already written such extension but, also, I cannot guarantee it.

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