Cheetah/Utils/Misc.py

   1 #!/usr/bin/env python
   2 # $Id: Misc.py,v 1.8 2005/11/02 22:26:08 tavis_rudd Exp $
   3 """Miscellaneous functions/objects used by Cheetah but also useful standalone.
   4
   5 Meta-Data
   6 ================================================================================
   7 Author: Mike Orr <iron@mso.oz.net>
   8 License: This software is released for unlimited distribution under the
   9          terms of the MIT license.  See the LICENSE file.
  10 Version: $Revision: 1.8 $
  11 Start Date: 2001/11/07
  12 Last Revision Date: $Date: 2005/11/02 22:26:08 $
  13 """
  14 __author__ = "Mike Orr <iron@mso.oz.net>"
  15 __revision__ = "$Revision: 1.8 $"[11:-2]
  16
  17 import os          # Used in mkdirsWithPyInitFile.
  18 import types       # Used in useOrRaise.
  19 import sys         # Used in die.
  20
  21 ##################################################
  22 ## MISCELLANEOUS FUNCTIONS
  23
  24 def die(reason):
  25     sys.stderr.write(reason + '\n')
  26     sys.exit(1)
  27
  28 def useOrRaise(thing, errmsg=''):
  29     """Raise 'thing' if it's a subclass of Exception.  Otherwise return it.
  30
  31     Called by: Cheetah.Servlet.cgiImport()
  32     """
  33     if type(thing) == types.ClassType and issubclass(thing, Exception):
  34         raise thing(errmsg)
  35     return thing
  36
  37
  38 def checkKeywords(dic, legalKeywords, what='argument'):
  39     """Verify no illegal keyword arguments were passed to a function.
  40
  41     in : dic, dictionary (**kw in the calling routine).
  42          legalKeywords, list of strings, the keywords that are allowed.
  43          what, string, suffix for error message (see function source).
  44     out: None.
  45     exc: TypeError if 'dic' contains a key not in 'legalKeywords'.
  46     called by: Cheetah.Template.__init__()
  47     """
  48     # XXX legalKeywords could be a set when sets get added to Python.
  49     for k in dic.keys(): # Can be dic.iterkeys() if Python >= 2.2.
  50         if k not in legalKeywords:
  51             raise TypeError("'%s' is not a valid %s" % (k, what))
  52
  53
  54 def removeFromList(list_, *elements):
  55     """Save as list_.remove(each element) but don't raise an error if
  56        element is missing.  Modifies 'list_' in place!  Returns None.
  57     """
  58     for elm in elements:
  59         try:
  60             list_.remove(elm)
  61         except ValueError:
  62             pass
  63
  64
  65 def mkdirsWithPyInitFiles(path):
  66     """Same as os.makedirs (mkdir 'path' and all missing parent directories)
  67        but also puts a Python '__init__.py' file in every directory it
  68        creates.  Does nothing (without creating an '__init__.py' file) if the
  69        directory already exists.
  70     """
  71     dir, fil = os.path.split(path)
  72     if dir and not os.path.exists(dir):
  73         mkdirsWithPyInitFiles(dir)
  74     if not os.path.exists(path):
  75         os.mkdir(path)
  76         init = os.path.join(path, "__init__.py")
  77         f = open(init, 'w') # Open and close to produce empty file.
  78         f.close()
  79
  80
  81
  82 # vim: shiftwidth=4 tabstop=4 expandtab