python-cinderclient/HACKING.rst

Cinder Client Style Commandments =========================

• Step 1: Read the OpenStack Style Commandments https://github.com/openstack-dev/hacking/blob/master/HACKING.rst
• Step 2: Read on

Cinder Client Specific Commandments ----------------------------

General

• Do not use locals(). Example:

  LOG.debug(_("volume %(vol_name)s: creating size %(vol_size)sG") %
            locals()) # BAD
  
  LOG.debug(_("volume %(vol_name)s: creating size %(vol_size)sG") %
            {'vol_name': vol_name,
             'vol_size': vol_size}) # OKAY

• Use 'raise' instead of 'raise e' to preserve original traceback or exception being reraised:

  except Exception as e:
      ...
      raise e  # BAD
  
  except Exception:
      ...
      raise  # OKAY

Text encoding ----------- All text within python code should be of type 'unicode'.

WRONG:

>>> s = 'foo' >>> s 'foo' >>> type(s) <type 'str'>

RIGHT:

>>> u = u'foo' >>> u u'foo' >>> type(u) <type 'unicode'>

• Transitions between internal unicode and external strings should always be immediately and explicitly encoded or decoded.

• All external text that is not explicitly encoded (database storage, commandline arguments, etc.) should be presumed to be encoded as utf-8.

  WRONG:

  mystring = infile.readline() myreturnstring = do_some_magic_with(mystring) outfile.write(myreturnstring)

  RIGHT:

  mystring = infile.readline() mytext = s.decode('utf-8') returntext = do_some_magic_with(mytext) returnstring = returntext.encode('utf-8') outfile.write(returnstring)