sqlutil Code

import locale 
import decimal
import datetime

zero = decimal.Decimal( 0 )

def chkzero( val ):
  if val == None: return zero
  return val

if getattr( locale, 'currency', None ) == None:       #python 2.4 non ha

  def _group(s):
    conv=locale.localeconv()
    grouping=conv['mon_grouping']
    if not grouping:return (s, 0)
    result=""
    seps = 0
    spaces = ""
    if s[-1] == ' ':
        sp = s.find(' ')
        spaces = s[sp:]
        s = s[:sp]
    while s and grouping:
        # if grouping is -1, we are done
        if grouping[0]==locale.CHAR_MAX:
            break
        # 0: re-use last group ad infinitum
        elif grouping[0]!=0:
            #process last group
            group=grouping[0]
            grouping=grouping[1:]
        if result:
            result=s[-group:]+conv['mon_thousands_sep']+result
            seps += 1
        else:
            result=s[-group:]
        s=s[:-group]
        if s and s[-1] not in "0123456789":
            # the leading string is only spaces and signs
            return s+result+spaces,seps
    if not result:
        return s+spaces,seps
    if s:
        result=s+conv['mon_thousands_sep']+result
        seps += 1
    return result+spaces,seps

  def formatmon( f, val, grouping=0 ):
    """Formats a value in the same way that the % formatting would use,
    but takes the current locale into account.
    Grouping is applied if the third parameter is true."""
    result = f % val
    fields = result.split(".")
    seps = 0
    if grouping:
        fields[0],seps=_group(fields[0])
    if len(fields)==2:
        result = fields[0]+locale.localeconv()['mon_decimal_point']+fields[1]
    elif len(fields)==1:
        result = fields[0]
    else:
        raise Error, "Too many decimal points in result string"
    while seps:
        # If the number was formatted for a specific width, then it
        # might have been filled with spaces to the left or right. If
        # so, kill as much spaces as there where separators.
        # Leading zeroes as fillers are not yet dealt with, as it is
        # not clear how they should interact with grouping.
        sp = result.find(" ")
        if sp==-1:break
        result = result[:sp]+result[sp+1:]
        seps -= 1
    return result
  
  def currency( val, symbol=False, grouping=False, international=False):
    # funzione presente solo in python 2.5
    if val is None: val = decimal.Decimal( 0 )
    conv = locale.localeconv()
    if international: 
      fmt = '%%.%df' % conv['int_frac_digits']
    else:
      fmt = '%%.%df' % conv['frac_digits']
    result = formatmon( fmt, val, grouping )
    if not symbol: return result
    if val < 0:
      symprec = conv['n_cs_precedes']
      symspace = conv['n_sep_by_space']
    else:
      symprec = conv['p_cs_precedes']
      symspace = conv['p_sep_by_space']
    if international:
      sym = conv['int_curr_symbol']
    else:
      sym = conv['currency_symbol']
    if symprec: 
      if symspace: result = sym + ' ' + result
      else:        result = sym + result
    else: 
      if symspace: result = result + ' ' + sym
      else:        result = result + sym
    return result
else:
  currency = locale.currency

def ocurrency( value, imon='EUR', omon='EUR', chg=None ):
  'mostra un valore espresso in una moneta in un\'altra'
  if imon == 'CVE': imon = 'EUR'
  if imon != omon:
    if chg == None: chg = cambiavalori()
    value = chg.convert( value, imon, omon )
  return currency( chkzero( value ), False, True, True )


def vcont2decimal( value, segno='A' ):
  vdec = decimal.Decimal( str( value ) )
  if segno == 'D': vdec = vdec * -1
  return vdec

def decimal2vcont( value ):
  if value < 0: return 'D', value * -1
  return 'A', value 

class cambiavalori:
  '''
  gestisce la conversione di un valore da una moneta ad un'altra
  '''
  def __init__( self, dtrif=None ):
    self.dtrif = dtrif or datetime.date.today()
    self.loadcache()
  #def read( self, mon ):
  #  return self.monin[mon]
    #except:
    #  pass # lancia query sql per definizione moneta
  def loadcache( self ):
    self._dbmon = {}
    # cerca nel db le monete presenti e scrive nella cache
    self._dbmon['EUR'] = [ decimal.Decimal( '1' ), 2 ]
    self._dbmon['ITL'] = [ decimal.Decimal( '1936.27' ), 0 ]
    self._dbmon['DEM'] = [ decimal.Decimal( '1.955830' ), 2 ]
    self._dbmon['FRL'] = [ decimal.Decimal( '40.339900' ), 2 ]
    self._dbmon['YEP'] = [ decimal.Decimal( '0.787564' ), 2 ]
    self._dbmon['ATS'] = [ decimal.Decimal( '13.7603' ), 2 ]
    self._dbmon['FIM'] = [ decimal.Decimal( '5.945730' ), 2 ]
    self._dbmon['FRF'] = [ decimal.Decimal( '6.559570' ), 2 ]
    self._dbmon['ESP'] = [ decimal.Decimal( '166.386' ), 2 ]
    self._dbmon['NLG'] = [ decimal.Decimal( '2.203710' ), 2 ]
    self._dbmon['PTE'] = [ decimal.Decimal( '200.482' ), 2 ]
    self._dbmon['GRD'] = [ decimal.Decimal( '340.75' ), 0 ]
  def retrieve( self, mon ):
    # cerca il cambio nel db e scrive nella cache
   return self._dbmon[mon]
  def cambio( self, mon ):
    try: vc = self._dbmon[mon]
    except IndexError: vc = self.retrieve( mon, self.dtrif )
    return vc[0]
  def convert( self, value, monfrom, monto='EUR' ):
    'converti un valore (decimal) da una moneta ad un\'altra (default EUR)'
    if value is not None: 
      value = value / self.cambio( monfrom )
      if monto != 'EUR': value = value * self.cambio( monto )
    return value
    

if __name__ == '__main__':
  locale.setlocale( locale.LC_ALL, '' )
  nr = decimal.Decimal('3456.78')
  print currency( nr, False, True, True )