pokedex/__init__.py

   1 # encoding: utf8
   2 import sys
   3
   4 from sqlalchemy.exc import IntegrityError
   5 import sqlalchemy.types
   6
   7 from .db import connect, metadata, tables as tables_module
   8
   9 def main():
  10     if len(sys.argv) <= 1:
  11         help()
  12
  13     command = sys.argv[1]
  14     args = sys.argv[2:]
  15
  16     # Find the command as a function in this file
  17     func = globals().get(command, None)
  18     if func and callable(func) and command != 'main':
  19         func(*args)
  20     else:
  21         help()
  22
  23
  24 def csvimport(engine_uri, directory='.'):
  25     import csv
  26
  27     from sqlalchemy.orm.attributes import instrumentation_registry
  28
  29     # Use autocommit in case rows fail due to foreign key incest
  30     session = connect(engine_uri, autocommit=True, autoflush=False)
  31
  32     metadata.create_all()
  33
  34     # SQLAlchemy is retarded and there is no way for me to get a list of ORM
  35     # classes besides to inspect the module they all happen to live in for
  36     # things that look right.
  37     table_base = tables_module.TableBase
  38     orm_classes = {}  # table object => table class
  39
  40     for name in dir(tables_module):
  41         # dir() returns strings!  How /convenient/.
  42         thingy = getattr(tables_module, name)
  43
  44         if not isinstance(thingy, type):
  45             # Not a class; bail
  46             continue
  47         elif not issubclass(thingy, table_base):
  48             # Not a declarative table; bail
  49             continue
  50         elif thingy == table_base:
  51             # Declarative table base, so not a real table; bail
  52             continue
  53
  54         # thingy is definitely a table class!  Hallelujah.
  55         orm_classes[thingy.__table__] = thingy
  56
  57     # Okay, run through the tables and actually load the data now
  58     for table_obj in metadata.sorted_tables:
  59         table_class = orm_classes[table_obj]
  60         table_name = table_obj.name
  61
  62         # Print the table name but leave the cursor in a fixed column
  63         print table_name + '...', ' ' * (40 - len(table_name)),
  64         sys.stdout.flush()
  65
  66         try:
  67             csvfile = open("%s/%s.csv" % (directory, table_name), 'rb')
  68         except IOError:
  69             # File doesn't exist; don't load anything!
  70             print 'no data!'
  71             continue
  72
  73         reader = csv.reader(csvfile, lineterminator='\n')
  74         column_names = [unicode(column) for column in reader.next()]
  75
  76         # Self-referential tables may contain rows with foreign keys of
  77         # other rows in the same table that do not yet exist.  We'll keep
  78         # a running list of these and try inserting them again after the
  79         # rest are done
  80         failed_rows = []
  81
  82         for csvs in reader:
  83             row = table_class()
  84
  85             for column_name, value in zip(column_names, csvs):
  86                 column = table_obj.c[column_name]
  87                 if column.nullable and value == '':
  88                     # Empty string in a nullable column really means NULL
  89                     value = None
  90                 elif isinstance(column.type, sqlalchemy.types.Boolean):
  91                     # Boolean values are stored as string values 0/1, but both
  92                     # of those evaluate as true; SQLA wants True/False
  93                     if value == '0':
  94                         value = False
  95                     else:
  96                         value = True
  97                 else:
  98                     # Otherwise, unflatten from bytes
  99                     value = value.decode('utf-8')
 100
 101                 setattr(row, column_name, value)
 102
 103             try:
 104                 session.add(row)
 105                 session.flush()
 106             except IntegrityError as e:
 107                 failed_rows.append(row)
 108
 109         # Loop over the failed rows and keep trying to insert them.  If a loop
 110         # doesn't manage to insert any rows, bail.
 111         do_another_loop = True
 112         while failed_rows and do_another_loop:
 113             do_another_loop = False
 114
 115             for i, row in enumerate(failed_rows):
 116                 try:
 117                     session.add(row)
 118                     session.flush()
 119
 120                     # Success!
 121                     del failed_rows[i]
 122                     do_another_loop = True
 123                 except IntegrityError as e:
 124                     pass
 125
 126         if failed_rows:
 127             print len(failed_rows), "rows failed"
 128         else:
 129             print 'loaded'
 130
 131 def csvexport(engine_uri, directory='.'):
 132     import csv
 133     session = connect(engine_uri)
 134
 135     for table_name in sorted(metadata.tables.keys()):
 136         print table_name
 137         table = metadata.tables[table_name]
 138
 139         writer = csv.writer(open("%s/%s.csv" % (directory, table_name), 'wb'),
 140                             lineterminator='\n')
 141         columns = [col.name for col in table.columns]
 142         writer.writerow(columns)
 143
 144         for row in session.query(table).all():
 145             csvs = []
 146             for col in columns:
 147                 # Convert Pythony values to something more universal
 148                 val = getattr(row, col)
 149                 if val == None:
 150                     val = ''
 151                 elif val == True:
 152                     val = '1'
 153                 elif val == False:
 154                     val = '0'
 155                 else:
 156                     val = unicode(val).encode('utf-8')
 157
 158                 csvs.append(val)
 159
 160             writer.writerow(csvs)
 161
 162
 163 def help():
 164     print u"""pokedex -- a command-line Pokédex interface
 165
 166     help                        Displays this message.
 167
 168   These commands are only useful for developers:
 169     csvimport {uri} [dir]       Import data from a set of CSVs to the database
 170                                   given by the URI.
 171     csvexport {uri} [dir]       Export data from the database given by the URI
 172                                   to a set of CSVs.
 173                                 Directory defaults to cwd.
 174 """
 175
 176     sys.exit(0)