Python editor writes Vim script example

The Vim plug-in is a. Vim script file that defines functions, mappings, syntax rules, and commands that you can use to manipulate windows, buffers, and rows. A general plug-in contains the command definition and event hooks. When you write a vim plug-in using Python, the function is written using VIML, although VIML is quick to learn, Python is more flexible, for example, you can use Urllib/httplib/simplejson to access certain WEB services, which is why a lot of the need to visit The plug-ins that ask Web services are written using VIML + Python.

Before you start writing plug-ins, you need to make sure that Vim supports Python by identifying the following commands:

Vim--version | grep +python
Let's go through a simple example to write a Vim plug-in in Python, which is used to get the Reddit home page information and display it on the current buffer.

First of all, in Vim, create a new Vimmit.vim file, we first need to determine whether to support Python, if you do not support the presentation message:

If!has (' Python ')
echo "error:required vim compiled with +python"
Finish
endif
The above code is written in Viml, and it checks to see if Vim supports Python.

Here is the Reddit () main function written in Python:

"Vim comments start with a double quote."
The Function definition is VIML. We can mix VIML and Python in
"Function definition.
function! Reddit ()

"We start the Python code like the next line.

Python << EOF
# The Vim module contains everything we need to interface with vim from
# python. We need urllib2 for the Web service consumer.
Import Vim, Urllib2
# We need JSON for parsing the response
Import JSON

# We define a timeout that we'll use the API call. We don ' t want
# users to wait so much.
TIMEOUT = 20
URL = "Http://reddit.com/.json"

Try
# Get the posts and parse the JSON response
Response = Urllib2.urlopen (URL, None, TIMEOUT). Read ()
Json_response = json.loads (response)

Posts = json_response.get ("Data", ""). Get ("Children", "")

# Vim.current.buffer is the current buffer. It ' s List-like object.
# Each line is a item in the list. We can loop through them delete
# them, alter them etc.
# Here we are delete all lines in the ' current buffer
Del vim.current.buffer[:]

# Here we append some lines above. Aesthetics.
Vim.current.buffer[0] = 80* "-"

    for post in posts:
        # into the next few lines, we get th E post details
        post_data = post.get ("Data", {})
   & nbsp;    up = Post_data.get ("Ups", 0)
        down = post_ Data.get ("Downs", 0)
        title = Post_data.get ("title", "NO title"). Encode ("Utf-8")
        score = post_data.get ("score", 0)
         permalink = Post_data.get ("permalink"). Encode ("Utf-8")
        url = post_data.get ("url"). Encode ("Utf-8")
        comments = Post_data.get (" Num_comments ")

# and here we are append line through to the buffer.
# The Upvotes
Vim.current.buffer.append ("↑%s"%up)
# Then the title and the URL
Vim.current.buffer.append ("%s [%s]"% (title, URL,))
# Then The Downvotes and number of comments
Vim.current.buffer.append ("↓%s | Comments:%s [%s] '% (down, comments, permalink,))
# and last we append some '-' for visual appeal.
Vim.current.buffer.append (80* "-")

Except Exception, E:
Print E

Eof

"Here's the Python code is closed." We can continue writing viml or Python again.
Endfunction
Save the file with the following command

: Source Vimmit.vim

Then call the plug-in:

: Call Reddit ()

This command is not easy to use, so we define a command:

command! -nargs=0 Reddit call Reddit ()

We defined the command: Reddit to call this function. The-nargs parameter declares how many parameters are in the command line.

Questions about function Parameters:

Q: How do I access parameters in a function?

function! Somename (Arg1, arg2, Arg3)
"Get the" the ' argument by name in VIML
Let FIRSTARG=A:ARG1

"Get the second argument by position in VIML
Let Secondarg=a:1

"Get the arguments in Python"

Python << EOF
Import Vim

First_argument = Vim.eval ("a:arg1") #or vim.eval ("a:0")
Second_argument = Vim.eval ("a:arg2") #or vim.eval ("A:1")
You can use ... To handle a variable number of parameters to replace a specific parameter name, which can be accessed by positional or named arguments, such as: (Arg1, arg2, ...)

Q: How do I invoke the Vim command in Python? Vim.command ("[Vim-command-here]")

Q: How do I define global variables and access them in VIML and Python?

Global variables use a shape like g:. prefix, you should check whether the variable is defined before defining a global variable:

If!exists ("G:reddit_apicall_timeout")
Let g:reddit_apicall_timeout=40
endif
You then access the variable in Python using the following code:

TIMEOUT = Vim.eval ("G:reddit_apicall_timeout")
You can reassign a global variable in the following ways:

Let g:reddit_apicall_timeout=60
For more information on using Python to write Vim Plug-ins, see the official documentation.