1  """ 
  2  Copyright 
  3  ========= 
  4      - Copyright: 2008-2009 Ad-Mail, Inc -- All rights reserved. 
  5      - Author: Ethan Furman 
  6      - Contact: ethan@stoneleaf.us 
  7      - Organization: Ad-Mail, Inc. 
  8      - Version: 0.88.016 as of 06 Dec 2010 
  9   
 10  Redistribution and use in source and binary forms, with or without 
 11  modification, are permitted provided that the following conditions are met: 
 12      - Redistributions of source code must retain the above copyright 
 13        notice, this list of conditions and the following disclaimer. 
 14      - Redistributions in binary form must reproduce the above copyright 
 15        notice, this list of conditions and the following disclaimer in the 
 16        documentation and/or other materials provided with the distribution. 
 17      - Neither the name of Ad-Mail, Inc nor the 
 18        names of its contributors may be used to endorse or promote products 
 19        derived from this software without specific prior written permission. 
 20   
 21  THIS SOFTWARE IS PROVIDED BY Ad-Mail, Inc ''AS IS'' AND ANY 
 22  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 23  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 24  DISCLAIMED. IN NO EVENT SHALL Ad-Mail, Inc BE LIABLE FOR ANY 
 25  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 26  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 27  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 
 28  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 29  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 30  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 31   
 32  B{I{Summary}} 
 33   
 34  Python package for reading/writing dBase III and VFP 6 tables and memos 
 35   
 36  The entire table is read into memory, and all operations occur on the in-memory 
 37  table, with data changes being written to disk as they occur. 
 38   
 39  Goals:  programming style with databases 
 40      - C{table = dbf.table('table name' [, fielddesc[, fielddesc[, ....]]])} 
 41          - fielddesc examples:  C{name C(30); age N(3,0); wisdom M; marriage D} 
 42      - C{record = [ table.current() | table[int] | table.append() | table.[next|prev|top|bottom|goto]() ]} 
 43      - C{record.field | record['field']} accesses the field 
 44   
 45  NOTE:  Of the VFP data types, auto-increment and null settings are not implemented. 
 46  """ 
 47  import os 
 48  import csv 
 49   
 50  from dbf.dates import Date, DateTime, Time 
 51  from dbf.exceptions import DbfWarning, Bof, Eof, DbfError, DataOverflow, FieldMissing, DoNotIndex 
 52  from dbf.tables import DbfTable, Db3Table, VfpTable, FpTable, List, DbfCsv 
 53  from dbf.tables import sql, ascii, codepage, encoding, version_map 
 54   
 55  version = (0, 88, 16) 
 56   
 57  default_type = 'db3'     
 58  sql_user_functions = {}       
 59   
 60  __docformat__ = 'epytext' 
 61   
 62 -def Table(filename, field_specs='', memo_size=128, ignore_memos=False, \ 
 63            read_only=False, keep_memos=False, meta_only=False, dbf_type=None, codepage=None): 
  64      "returns an open table of the correct dbf_type, or creates it if field_specs is given" 
 65       
 66      if field_specs and dbf_type is None: 
 67          dbf_type = default_type 
 68      if dbf_type is not None: 
 69          dbf_type = dbf_type.lower() 
 70          if dbf_type == 'db3': 
 71              return Db3Table(filename, field_specs, memo_size, ignore_memos, read_only, keep_memos, meta_only, codepage) 
 72          elif dbf_type == 'fp': 
 73              return FpTable(filename, field_specs, memo_size, ignore_memos, read_only, keep_memos, meta_only, codepage) 
 74          elif dbf_type == 'vfp': 
 75              return VfpTable(filename, field_specs, memo_size, ignore_memos, read_only, keep_memos, meta_only, codepage) 
 76          elif dbf_type == 'dbf': 
 77              return DbfTable(filename, field_specs, memo_size, ignore_memos, read_only, keep_memos, meta_only, codepage) 
 78          else: 
 79              raise DbfError("Unknown table type: %s" % dbf_type) 
 80      else: 
 81          possibles = guess_table_type(filename) 
 82          if len(possibles) == 1: 
 83              return possibles[0][2](filename, field_specs, memo_size, ignore_memos, \ 
 84                                   read_only, keep_memos, meta_only) 
 85          else: 
 86              for type, desc, cls in possibles: 
 87                  if type == default_type: 
 88                      return cls(filename, field_specs, memo_size, ignore_memos, \ 
 89                                   read_only, keep_memos, meta_only) 
 90              else: 
 91                  types = ', '.join(["%s" % item[1] for item in possibles]) 
 92                  abbrs = '[' + ' | '.join(["%s" % item[0] for item in possibles]) + ']' 
 93                  raise DbfError("Table could be any of %s.  Please specify %s when opening" % (types, abbrs)) 
  95      "returns integers 0 - len(sequence)" 
 96      for i in xrange(len(sequence)): 
 97          yield i     
 122   
124      "adds fields to an existing table" 
125      table = Table(table) 
126      try: 
127          table.add_fields(field_specs) 
128      finally: 
129          table.close() 
 137 -def export(table, filename='', fields='', format='csv', header=True): 
 138      "creates a csv or tab-delimited file from an existing table" 
139      if fields is None: 
140          fields = [] 
141      table = Table(table) 
142      try: 
143          table.export(filename=filename, field_specs=fields, format=format, header=header) 
144      finally: 
145          table.close() 
 147      "prints the first record of a table" 
148      table = Table(table) 
149      try: 
150          print str(table[0]) 
151      finally: 
152          table.close() 
 153 -def from_csv(csvfile, to_disk=False, filename=None, field_names=None, extra_fields=None, dbf_type='db3', memo_size=64, min_field_size=1): 
 154      """creates a Character table from a csv file 
155      to_disk will create a table with the same name 
156      filename will be used if provided 
157      field_names default to f0, f1, f2, etc, unless specified (list) 
158      extra_fields can be used to add additional fields -- should be normal field specifiers (list)""" 
159      reader = csv.reader(open(csvfile)) 
160      if field_names: 
161          field_names = ['%s M' % fn for fn in field_names] 
162      else: 
163          field_names = ['f0 M'] 
164      mtable = Table(':memory:', [field_names[0]], dbf_type=dbf_type, memo_size=memo_size) 
165      fields_so_far = 1 
166      for row in reader: 
167          while fields_so_far < len(row): 
168              if fields_so_far == len(field_names): 
169                  field_names.append('f%d M' % fields_so_far) 
170              mtable.add_fields(field_names[fields_so_far]) 
171              fields_so_far += 1 
172          mtable.append(tuple(row)) 
173      if filename: 
174          to_disk = True 
175      if not to_disk: 
176          if extra_fields: 
177              mtable.add_fields(extra_fields) 
178      else: 
179          if not filename: 
180              filename = os.path.splitext(csvfile)[0] 
181          length = [min_field_size] * len(field_names) 
182          for record in mtable: 
183              for i in index(record.field_names): 
184                  length[i] = max(length[i], len(record[i])) 
185          fields = mtable.field_names 
186          fielddef = [] 
187          for i in index(length): 
188              if length[i] < 255: 
189                  fielddef.append('%s C(%d)' % (fields[i], length[i])) 
190              else: 
191                  fielddef.append('%s M' % (fields[i])) 
192          if extra_fields: 
193              fielddef.extend(extra_fields) 
194          csvtable = Table(filename, fielddef, dbf_type=dbf_type) 
195          for record in mtable: 
196              csvtable.append(record.scatter_fields()) 
197          return csvtable 
198      return mtable 
 200      "returns the list of field names of a table" 
201      table = Table(table) 
202      return table.field_names 
 204      "prints table info" 
205      table = Table(table) 
206      print str(table) 
 208      "renames a field in a table" 
209      table = Table(table) 
210      try: 
211          table.rename_field(oldfield, newfield) 
212      finally: 
213          table.close() 
 215      "returns the definition of a field (or all fields)" 
216      table = Table(table) 
217      return table.structure(field) 
 219      "just what it says ;)" 
220      for index,dummy in enumerate(records): 
221          chars = dummy._data 
222          print "%2d: " % index, 
223          for char in chars[1:]: 
224              print " %2x " % ord(char), 
225          print 
 226