Re: Flexable Collating (feedback please)



This is how I changed it...

(I edited out the test and imports for posting here.)



locale.setlocale(locale.LC_ALL, '') # use current locale settings

class Collate(object):
""" A general purpose and configurable collator class.
"""
options = [ 'CAPS_FIRST', 'NUMERICAL', 'HYPHEN_AS_SPACE',
'UNDERSCORE_AS_SPACE', 'IGNORE_LEADING_WS',
'IGNORE_COMMAS', 'PERIOD_AS_COMMAS' ]

def __init__(self, flags=""):
if flags:
flags = flags.upper().split()
for value in flags:
if value not in self.options:
raise ValueError, 'Invalid option: %s' % value
self.txtable = []
if 'HYPHEN_AS_SPACE' in flags:
self.txtable.append(('-', ' '))
if 'UNDERSCORE_AS_SPACE' in flags:
self.txtable.append(('_', ' '))
if 'PERIOD_AS_COMMAS' in flags:
self.txtable.append(('.', ','))
if 'IGNORE_COMMAS' in flags:
self.txtable.append((',', ''))
self.flags = flags
self.numrex = re.compile(r'([\d\.]*|\D*)', re.LOCALE)

def transform(self, s):
""" Transform a string for collating.
"""
if not self.flags:
return locale.strxfrm(s)
for a, b in self.txtable:
s = s.replace(a, b)
if 'IGNORE_LEADING_WS' in self.flags:
s = s.strip()
if 'CAPS_FIRST' in self.flags:
s = s.swapcase()
if 'NUMERICAL' in self.flags:
slist = self.numrex.split(s)
for i, x in enumerate(slist):
try:
slist[i] = float(x)
except:
slist[i] = locale.strxfrm(x)
return slist
return locale.strxfrm(s)

def __call__(self, a):
""" This allows the Collate class to be used as a sort key.

USE: list.sort(key=Collate(flags))
"""
return self.transform(a)

def collate(slist, flags=[]):
""" Collate list of strings in place.
"""
slist.sort(key=Collate(flags).transform)

def collated(slist, flags=[]):
""" Return a collated list of strings.
"""
return sorted(slist, key=Collate(flags).transform)

.

Relevant Pages

  • Re: Flexible Collating (feedback please)
    ... Although it is still quite a bit slower than a bare list.sort, that is to be expected as collate is locale aware and does additional transformations on the data which you would need to do anyways. ... Changed the flag types from integer values to a list of named strings. ... The reason for this is it makes finding errors easier and you can examine the flags attribute and get a readable list of flags. ... It now separates numerals in the middle of the string. ...
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  • Re: Flexible Collating (feedback please)
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