• đź“… Nov 17, 2013 🏷️ Vim

    Pasting with vim and indentation issues

    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.

  • đź“… Sep 12, 2013 🏷️ Productivity

    Remap your Caps Lock

    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.

  • đź“… Jul 22, 2013 🏷️ Programming

    Python doctests and decorators bug

    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.
  • đź“… Jul 22, 2013 🏷️ Programming

    Python tests with doctest and unittest

    When it comes to tests, doctest is a great simple module to write tests for your application. However it is pretty basic and does not have any extended features like, for example, centralized unit tests. If you have multiple modules with doctests (and you probably do) you most likely want to be able to run all doctests recursively from one place. That’s where unittest comes in.

    Let’s assume we store modules in the lib/ directory:

    $ ls lib/
__init__.py bar.py foo.py

    Here are the contents of foo.py and bar.py respectfully:

    def foo():
    """
    >>> foo()
    False
    """
    return False

def bar():
    """
    >>> bar()
    True
    """
    return True

def baz():
    """
    >>> baz()
    False
    """
    return False

    Now, to run all tests we need a wrapper script. Let’s call it: runtests.py:

    #!/usr/bin/env python

import unittest
import doctest
import os

files = []
root_dir = 'lib/'

for root, _, filenames in os.walk(root_dir):
    for filename in filenames:
        if filename == '__init__.py' or filename[-3:] != '.py':
            continue
        f = os.path.join(root, filename)
        f = f.replace('/', '.')
        f = f[:-3]
        files.append(f)

suite = unittest.TestSuite()
for module in files:
    suite.addTest(doctest.DocTestSuite(module))
unittest.TextTestRunner(verbosity=1).run(suite)

    This approach invokes the doctest.DocTestSuite method, which converts doctests strings into unittest suites. Time to run our tests:

    $ chmod +x runtests.py
$ ./runtests.py
...
----------------------------------------------------------------------
Ran 3 tests in 0.008s

OK

    And just to be sure that approach actually works, let’s make one of the tests fail:

    $ ./runtests.py
.F.
======================================================================
FAIL: baz (lib.bar)
Doctest: lib.bar.baz
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/doctest.py", line 2201, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for lib.bar.baz
  File "/home/rosipov/unitdoc/lib/bar.py", line 8, in baz

----------------------------------------------------------------------
File "/home/rosipov/unitdoc/lib/bar.py", line 10, in lib.bar.baz
Failed example:
    baz()
Expected:
    True
Got:
    False

----------------------------------------------------------------------
Ran 3 tests in 0.009s

FAILED (failures=1)
  • đź“… Jun 27, 2013 🏷️ Programming

    pygame.font not found

    I had an issue with pygame not being able to find a dependency for the font module. After quite a time-consuming search the missing package name was libsdl-ttf2.0-dev.

    Hope this helps someone.