You can open previous location by hitting Ctrl-O. You can prefix the command with a number to go multiple files back. You can also travel forward in “file history” by using Ctrl-I.

There’s a nice article on Vim Wikia with more details on a subject.

If you use git VCS, you can view previous version of the file you are currently editing in a split window by executing following command:

:vsp tmp | read !git show HEAD^:path/from/working/directory

For the instant syntax highlighting, you can specify temporary file’s extension, like following:

:vsp tmp.py | read !git show HEAD^:lib/module.py

You can also cycle back by few versions by replacing HEAD^ (which points to the previous commit) with HEAD~N, where N is the number of commits you would like to go back in history by. For example, if you would like to get a version of the file 4 commits ago - you can do so by executing following command:

:vsp tmp | read !git show HEAD~4:path/from/working/directory

It’s a pretty nice hack when you need to quickly view previous version of the file you are working on.

If you use vim often - you probably had to paste something into vim from the outside source. And, if you have corresponding indentation rules, they will get applied, turning your nice block of code into something that looks more like a case of stairs:

def foo(a, b):
        a, b = b, a
            print "I am doing something important."
                return a - b

Quite nasty, isn’t it? But that’s where vim’s paste option comes in. Before pasting, execute :set paste. If you go into insert mode, you’ll see the usual mode indicator switch to -- INSERT (paste) --. Try pasting the same block of code now:

def foo(a, b):
    a, b = b, a
    print "I am doing something important."
    return a - b

Beautiful. Don’t forget to switch back to a regular mode by executing :set nopaste.

The following three paragraphs are an angry Caps Lock rant. Feel free to skip past it or join me by commenting below.

I’ve had it with Caps Lock! How many times did I accidentally press it while hitting the A key! How many times did I mean Tab or Shift! There is an obvious problem with the Caps Lock placement, and there being only a millimeter of space to designate it from an adjacent key, it is quite difficult to notice when you accidentally press it.

Pushing Caps Lock is more tolerable when typing, but while using keyboard controlled software it’s a real pain; vim turns into a beeping ravaging nightmare, vimperator messes up all your bookmarks… Same thing with websites supporting keyboard shortcuts.

When was the last time I ever used Caps Lock? Over ten years ago, when I was playing a video game that used Caps Lock to switch between running and walking. Em… Seriously? Time to put an end this nonsense.

Linux and Mac

Drop this into your ~/bin/capslockremap, and don’t forget to chmod +x ~/bin/capslockremap. Now run the script with root privileges (that’ll last you until the next restart).

#!/bin/sh

# This temporarily remaps the Caps Lock key to a Control key.
# The keyboard will return to the previous settings after a
# reboot. The Linux console and the X Window system each
# handles keypresses separately, so each must be remapped
# separately. First remap the X keyboard since this does not
# require root access.

# Remap the Caps Lock key to a Control key for
# the X Window system.
if type setxkbmap >/dev/null 2>&1; then
fi

# You have to be root to remap the console keyboard.
if [ "$(id -u)" != "0" ]; then
  echo "This script is not running as root so"
  echo "the console Caps Lock cannot be remapped."
  echo "Perhaps you forgot to run this under sudo."
  echo "Note that this problem does not effect X."
  echo "This only effects the consoles running on"
  echo "Alt-f1 through Alt-f6."
  exit 2
fi
# Remap the CapsLock key to a Control key for the console.
(dumpkeys | grep keymaps; echo "keycode 58 = Control") | loadkeys

Windows

Download Sysinternals Ctrl2Cap v2.0, run it as Administrator with install flag: ctrl2cap.exe /install.

Source CapsLock Remap Howto - Noah.org.

Now, this as well might be a feature, but doctest strings are not being executed for decorated functions (at least in version 2.7). However, there is a workaround.

You need to decorate your functions with functools.wraps within a decorator to import docstrings into a decorator scope.

#!/usr/bin/env python

from functools import wraps

def decorator(func):
    @wraps(func)
    def wrapper():
        return func()
    return wrapper

@decorator
def foo():
    """
    >>> foo()
    False
    """
    return True

import doctest
doctest.testmod()

Now you can see this test failing, where otherwise it would have been ignored:

**********************************************************************
File "decorator.py", line 12, in __main__.foo
Failed example:
    foo()
Expected:
    False
Got:
    True
**********************************************************************
1 items had failures:
   1 of   1 in __main__.foo
***Test Failed*** 1 failures.