18. November 2012

Vim – How to edit Unicode files produced by PowerShell

It’s possible to redirect output of PowerShell command into file. E.g.:

Get-ChildItem -Recurse  | Select-Object -ExpandProperty FullName >file-list.txt

If you want to open this file-list.txt by vim you may be little bit surprised by unreadable text:

If you open the same file in notepad, then everything is perfectly readable.

There is simple fix for vim suggested by Tony Mechelynck. Just open .vimrc in your home directory and add following lines:

if has('multi_byte')                   " multibyte features compiled-in 
  if &encoding !~? '^u'                " the OS locale is not Unicode 
    if &termencoding == ''             " empty means 'use &enc' 
      let &termencoding = &encoding    " avoid clobbering keyboard codes 
    endif 
    set encoding=utf-8 " we can do it, now that the kb is taken care of 
  endif 
  set fileencodings=ucs-bom,utf-8,latin1 " heuristics for existing files 
  setglobal bomb fileencoding=latin1   " defaults for new files 
                     " 'bomb' doesn't apply to latin1 
                     " it applies when 'fenc' is manually set to Unicode 
endif

Result:

20. August 2012

Problems with deploying Heroku Django app from Windows

Deploying Django app to Heroku from Windows machine is little bit tricky.

You can follow instructions in Heroku manual. The first problem that you may encounter is with Postgres support in Python. There is problem with this command:

pip install Django psycopg2 dj-database-url

If you do not have Visual Studio installed on your machine, you’ll receive error that vcvarsall.bat is missing.

Solution is quite easy. You don’t need to install Visaul Studio. Just download binary version of psycopg2 module from http://www.stickpeople.com/projects/python/win-psycopg/

Then you can exclude psycopg2 from pip install command, because it is installed in system directory of Python.

Another tricky issue is with command:

pip freeze >requirements.txt

If you type this command in PowerShell then it will automatically create Unicode file with extra bytes. When you try to deploy project with messed requirements.txt to Herou then you’ll see self explanatory error ;-)

TypeError: must be encoded string without NULL bytes, not str

Nice :-)

Just open requirements.txt file with notepad and select Save as. In Save as dialog choose ANSI.

Commit file and push project to Heroku. It will work ;)