The following packages have unmet dependencies:
 vim-nox : Depends: vim-common (= 2:7.3.547-7) but 2:7.4.488-7 is to be installed
           Depends: libperl5.14 (>= 5.14.2) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

How to solve it?

sudo apt-get remove vim-common

The following packages have unmet dependencies:
 vim-nox : Depends: vim-common (= 2:7.4.1689-3ubuntu1) but 2:7.4.1689-3ubuntu1.2 is to be installed
           Depends: vim-runtime (= 2:7.4.1689-3ubuntu1) but 2:7.4.1689-3ubuntu1.2 is to be installed

sudo apt-get remove vim-runtime

sudo apt-get install vim-nox

Install Vundle

Vundle yes vim One of the many plug-in managers is also one of the most widely used. install Vundle:
git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim

touch ~/.vimrc

Add configuration files

"vundle
set nocompatible
filetype off

set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()

Plugin 'VundleVim/Vundle.vim'
"git interface
Plugin 'tpope/vim-fugitive'
"filesystem
Plugin 'scrooloose/nerdtree'
Plugin 'jistr/vim-nerdtree-tabs'
Plugin 'kien/ctrlp.vim' 

"html
"  isnowfy only compatible with python not python3
Plugin 'isnowfy/python-vim-instant-markdown'
Plugin 'jtratner/vim-flavored-markdown'
Plugin 'suan/vim-instant-markdown'
Plugin 'nelstrom/vim-markdown-preview'
"python sytax checker
Plugin 'nvie/vim-flake8'
Plugin 'vim-scripts/Pydiction'
Plugin 'vim-scripts/indentpython.vim'
Plugin 'scrooloose/syntastic'

"auto-completion stuff
"Plugin 'klen/python-mode'
Plugin 'Valloric/YouCompleteMe'
Plugin 'klen/rope-vim'
"Plugin 'davidhalter/jedi-vim'
Plugin 'ervandew/supertab'
""code folding
Plugin 'tmhedberg/SimpylFold'

"Colors!!!
Plugin 'altercation/vim-colors-solarized'
Plugin 'jnurmine/Zenburn'

call vundle#end()

filetype plugin indent on    " enables filetype detection
let g:SimpylFold_docstring_preview = 1

"autocomplete
let g:ycm_autoclose_preview_window_after_completion=1

"custom keys
let mapleader=" "
map <leader>g  :YcmCompleter GoToDefinitionElseDeclaration<CR>
"
call togglebg#map("<F5>")
"colorscheme zenburn
"set guifont=Monaco:h14

let NERDTreeIgnore=['\.pyc$', '\~$'] "ignore files in NERDTree

"I don't like swap files
set noswapfile

"turn on numbering
set nu

"python with virtualenv support
py << EOF
import os.path
import sys
import vim
if 'VIRTUA_ENV' in os.environ:
  project_base_dir = os.environ['VIRTUAL_ENV']
  sys.path.insert(0, project_base_dir)
  activate_this = os.path.join(project_base_dir,'bin/activate_this.py')
  execfile(activate_this, dict(__file__=activate_this))
EOF

"it would be nice to set tag files by the active virtualenv here
":set tags=~/mytags "tags for ctags and taglist
"omnicomplete
autocmd FileType python set omnifunc=pythoncomplete#Complete

"------------Start Python PEP 8 stuff----------------
" Number of spaces that a pre-existing tab is equal to.
au BufRead,BufNewFile *py,*pyw,*.c,*.h set tabstop=4

"spaces for indents
au BufRead,BufNewFile *.py,*pyw set shiftwidth=4
au BufRead,BufNewFile *.py,*.pyw set expandtab
au BufRead,BufNewFile *.py set softtabstop=4

" Use the below highlight group when displaying bad whitespace is desired.
highlight BadWhitespace ctermbg=red guibg=red

" Display tabs at the beginning of a line in Python mode as bad.
au BufRead,BufNewFile *.py,*.pyw match BadWhitespace /^\t\+/
" Make trailing whitespace be flagged as bad.
au BufRead,BufNewFile *.py,*.pyw,*.c,*.h match BadWhitespace /\s\+$/

" Wrap text after a certain number of characters
au BufRead,BufNewFile *.py,*.pyw, set textwidth=100

" Use UNIX (\n) line endings.
au BufNewFile *.py,*.pyw,*.c,*.h set fileformat=unix

" Set the default file encoding to UTF-8:
set encoding=utf-8

" For full syntax highlighting:
let python_highlight_all=1
syntax on

" Keep indentation level from previous line:
autocmd FileType python set autoindent

" make backspaces more powerfull
set backspace=indent,eol,start


"Folding based on indentation:
autocmd FileType python set foldmethod=indent
"use space to open folds
nnoremap <space> za 
"----------Stop python PEP 8 stuff--------------

"js stuff"
autocmd FileType javascript setlocal shiftwidth=2 tabstop=2
© 2017 GitHub, Inc.

Paste it over, one at a time. Then execute in last line mode

PluginInstall

YouCompleteMe

The languages supported by YouCompleteMe are:

C,Objectiv-c,C#,C++,Objectiv-C++,Php,Javascript,Typescript,python,Go,Rust

Installation requires only one command:

There are many configuration options involved in YouCompleteMe, which I don't fully understand. In addition, I personally feel that Syntactic's tips are a bit ugly, so there is no installation. Here is a list of what I'm using. Please check the official documents for details:

"Default profile path"
let g:ycm_global_ycm_extra_conf = '~/.ycm_extra_conf.py'
"open vim No more queries about loading ycm_extra_conf.py To configure"
let g:ycm_confirm_extra_conf=0
set completeopt=longest,menu
"python Interpreter Path"
let g:ycm_path_to_python_interpreter='/usr/local/bin/python'
"Whether to Turn on Semantic Completion"
let g:ycm_seed_identifiers_with_syntax=1
"Is Completion Opened in Notes"
let g:ycm_complete_in_comments=1
let g:ycm_collect_identifiers_from_comments_and_strings = 0
"Number of Characters Starting Completion"
let g:ycm_min_num_of_chars_for_completion=2
"Automatic shutdown preview window after completion"
let g:ycm_autoclose_preview_window_after_completion=1
" Disallow caching matches,Reproduce the matches every time"
let g:ycm_cache_omnifunc=0
"Completion is also turned on in strings"
let g:ycm_complete_in_strings = 1
"Automatically close the preview window after leaving insert mode"
autocmd InsertLeave * if pumvisible() == 0|pclose|endif
"Check the current item when returning"
inoremap <expr> <CR>       pumvisible() ? '<C-y>' : '\<CR>'     
"Upper and Lower Key Behavior"
inoremap <expr> <Down>     pumvisible() ? '\<C-n>' : '\<Down>'
inoremap <expr> <Up>       pumvisible() ? '\<C-p>' : '\<Up>'
inoremap <expr> <PageDown> pumvisible() ? '\<PageDown>\<C-p>\<C-n>' : '\<PageDown>'
inoremap <expr> <PageUp>   pumvisible() ? '\<PageUp>\<C-p>\<C-n>' : '\<PageUp>'

vim-powerline

Some additional suggestions

Reference articles

http://www.jianshu.com/p/f0513d18742a
https://segmentfault.com/a/1190000003962806
http://learnvimscriptthehardway.stevelosh.com/
http://blog.csdn.net/github_33934628/article/details/51854843