-
Notifications
You must be signed in to change notification settings - Fork 1.4k
/
dataset.py
462 lines (372 loc) · 14.1 KB
/
dataset.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
import csv
import datetime
from decimal import Decimal
import json
import operator
try:
from urlparse import urlparse
except ImportError:
from urllib.parse import urlparse
import sys
import uuid
from peewee import *
from playhouse.db_url import connect
from playhouse.migrate import migrate
from playhouse.migrate import SchemaMigrator
from playhouse.reflection import Introspector
if sys.version_info[0] == 3:
basestring = str
from functools import reduce
def open_file(f, mode, encoding='utf8'):
return open(f, mode, encoding=encoding)
else:
def open_file(f, mode, encoding='utf8'):
return open(f, mode)
class DataSet(object):
def __init__(self, url, include_views=False, **kwargs):
if isinstance(url, Database):
self._url = None
self._database = url
self._database_path = self._database.database
else:
self._url = url
parse_result = urlparse(url)
self._database_path = parse_result.path[1:]
# Connect to the database.
self._database = connect(url)
# Open a connection if one does not already exist.
self._database.connect(reuse_if_open=True)
# Introspect the database and generate models.
self._introspector = Introspector.from_database(self._database)
self._include_views = include_views
self._models = self._introspector.generate_models(
skip_invalid=True,
literal_column_names=True,
include_views=self._include_views,
**kwargs)
self._migrator = SchemaMigrator.from_database(self._database)
class BaseModel(Model):
class Meta:
database = self._database
self._base_model = BaseModel
self._export_formats = self.get_export_formats()
self._import_formats = self.get_import_formats()
def __repr__(self):
return '<DataSet: %s>' % self._database_path
def get_export_formats(self):
return {
'csv': CSVExporter,
'json': JSONExporter,
'tsv': TSVExporter}
def get_import_formats(self):
return {
'csv': CSVImporter,
'json': JSONImporter,
'tsv': TSVImporter}
def __getitem__(self, table):
if table not in self._models and table in self.tables:
self.update_cache(table)
return Table(self, table, self._models.get(table))
@property
def tables(self):
tables = self._database.get_tables()
if self._include_views:
tables += self.views
return tables
@property
def views(self):
return [v.name for v in self._database.get_views()]
def __contains__(self, table):
return table in self.tables
def connect(self, reuse_if_open=False):
self._database.connect(reuse_if_open=reuse_if_open)
def close(self):
self._database.close()
def update_cache(self, table=None):
if table:
dependencies = [table]
if table in self._models:
model_class = self._models[table]
dependencies.extend([
related._meta.table_name for _, related, _ in
model_class._meta.model_graph()])
else:
dependencies.extend(self.get_table_dependencies(table))
else:
dependencies = None # Update all tables.
self._models = {}
updated = self._introspector.generate_models(
skip_invalid=True,
table_names=dependencies,
literal_column_names=True,
include_views=self._include_views)
self._models.update(updated)
def get_table_dependencies(self, table):
stack = [table]
accum = []
seen = set()
while stack:
table = stack.pop()
for fk_meta in self._database.get_foreign_keys(table):
dest = fk_meta.dest_table
if dest not in seen:
stack.append(dest)
accum.append(dest)
return accum
def __enter__(self):
self.connect()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if not self._database.is_closed():
self.close()
def query(self, sql, params=None):
return self._database.execute_sql(sql, params)
def transaction(self):
return self._database.atomic()
def _check_arguments(self, filename, file_obj, format, format_dict):
if filename and file_obj:
raise ValueError('file is over-specified. Please use either '
'filename or file_obj, but not both.')
if not filename and not file_obj:
raise ValueError('A filename or file-like object must be '
'specified.')
if format not in format_dict:
valid_formats = ', '.join(sorted(format_dict.keys()))
raise ValueError('Unsupported format "%s". Use one of %s.' % (
format, valid_formats))
def freeze(self, query, format='csv', filename=None, file_obj=None,
encoding='utf8', **kwargs):
self._check_arguments(filename, file_obj, format, self._export_formats)
if filename:
file_obj = open_file(filename, 'w', encoding)
exporter = self._export_formats[format](query)
exporter.export(file_obj, **kwargs)
if filename:
file_obj.close()
def thaw(self, table, format='csv', filename=None, file_obj=None,
strict=False, encoding='utf8', **kwargs):
self._check_arguments(filename, file_obj, format, self._export_formats)
if filename:
file_obj = open_file(filename, 'r', encoding)
importer = self._import_formats[format](self[table], strict)
count = importer.load(file_obj, **kwargs)
if filename:
file_obj.close()
return count
class Table(object):
def __init__(self, dataset, name, model_class):
self.dataset = dataset
self.name = name
if model_class is None:
model_class = self._create_model()
model_class.create_table()
self.dataset._models[name] = model_class
@property
def model_class(self):
return self.dataset._models[self.name]
def __repr__(self):
return '<Table: %s>' % self.name
def __len__(self):
return self.find().count()
def __iter__(self):
return iter(self.find().iterator())
def _create_model(self):
class Meta:
table_name = self.name
return type(
str(self.name),
(self.dataset._base_model,),
{'Meta': Meta})
def create_index(self, columns, unique=False):
index = ModelIndex(self.model_class, columns, unique=unique)
self.model_class.add_index(index)
self.dataset._database.execute(index)
def _guess_field_type(self, value):
if isinstance(value, basestring):
return TextField
if isinstance(value, (datetime.date, datetime.datetime)):
return DateTimeField
elif value is True or value is False:
return BooleanField
elif isinstance(value, int):
return IntegerField
elif isinstance(value, float):
return FloatField
elif isinstance(value, Decimal):
return DecimalField
return TextField
@property
def columns(self):
return [f.name for f in self.model_class._meta.sorted_fields]
def _migrate_new_columns(self, data):
new_keys = set(data) - set(self.model_class._meta.fields)
new_keys -= set(self.model_class._meta.columns)
if new_keys:
operations = []
for key in new_keys:
field_class = self._guess_field_type(data[key])
field = field_class(null=True)
operations.append(
self.dataset._migrator.add_column(self.name, key, field))
field.bind(self.model_class, key)
migrate(*operations)
self.dataset.update_cache(self.name)
def __getitem__(self, item):
try:
return self.model_class[item]
except self.model_class.DoesNotExist:
pass
def __setitem__(self, item, value):
if not isinstance(value, dict):
raise ValueError('Table.__setitem__() value must be a dict')
pk = self.model_class._meta.primary_key
value[pk.name] = item
try:
with self.dataset.transaction() as txn:
self.insert(**value)
except IntegrityError:
self.dataset.update_cache(self.name)
self.update(columns=[pk.name], **value)
def __delitem__(self, item):
del self.model_class[item]
def insert(self, **data):
self._migrate_new_columns(data)
return self.model_class.insert(**data).execute()
def _apply_where(self, query, filters, conjunction=None):
conjunction = conjunction or operator.and_
if filters:
expressions = [
(self.model_class._meta.fields[column] == value)
for column, value in filters.items()]
query = query.where(reduce(conjunction, expressions))
return query
def update(self, columns=None, conjunction=None, **data):
self._migrate_new_columns(data)
filters = {}
if columns:
for column in columns:
filters[column] = data.pop(column)
return self._apply_where(
self.model_class.update(**data),
filters,
conjunction).execute()
def _query(self, **query):
return self._apply_where(self.model_class.select(), query)
def find(self, **query):
return self._query(**query).dicts()
def find_one(self, **query):
try:
return self.find(**query).get()
except self.model_class.DoesNotExist:
return None
def all(self):
return self.find()
def delete(self, **query):
return self._apply_where(self.model_class.delete(), query).execute()
def freeze(self, *args, **kwargs):
return self.dataset.freeze(self.all(), *args, **kwargs)
def thaw(self, *args, **kwargs):
return self.dataset.thaw(self.name, *args, **kwargs)
class Exporter(object):
def __init__(self, query):
self.query = query
def export(self, file_obj):
raise NotImplementedError
class JSONExporter(Exporter):
def __init__(self, query, iso8601_datetimes=False):
super(JSONExporter, self).__init__(query)
self.iso8601_datetimes = iso8601_datetimes
def _make_default(self):
datetime_types = (datetime.datetime, datetime.date, datetime.time)
if self.iso8601_datetimes:
def default(o):
if isinstance(o, datetime_types):
return o.isoformat()
elif isinstance(o, (Decimal, uuid.UUID)):
return str(o)
raise TypeError('Unable to serialize %r as JSON' % o)
else:
def default(o):
if isinstance(o, datetime_types + (Decimal, uuid.UUID)):
return str(o)
raise TypeError('Unable to serialize %r as JSON' % o)
return default
def export(self, file_obj, **kwargs):
json.dump(
list(self.query),
file_obj,
default=self._make_default(),
**kwargs)
class CSVExporter(Exporter):
def export(self, file_obj, header=True, **kwargs):
writer = csv.writer(file_obj, **kwargs)
tuples = self.query.tuples().execute()
tuples.initialize()
if header and getattr(tuples, 'columns', None):
writer.writerow([column for column in tuples.columns])
for row in tuples:
writer.writerow(row)
class TSVExporter(CSVExporter):
def export(self, file_obj, header=True, **kwargs):
kwargs.setdefault('delimiter', '\t')
return super(TSVExporter, self).export(file_obj, header, **kwargs)
class Importer(object):
def __init__(self, table, strict=False):
self.table = table
self.strict = strict
model = self.table.model_class
self.columns = model._meta.columns
self.columns.update(model._meta.fields)
def load(self, file_obj):
raise NotImplementedError
class JSONImporter(Importer):
def load(self, file_obj, **kwargs):
data = json.load(file_obj, **kwargs)
count = 0
for row in data:
if self.strict:
obj = {}
for key in row:
field = self.columns.get(key)
if field is not None:
obj[field.name] = field.python_value(row[key])
else:
obj = row
if obj:
self.table.insert(**obj)
count += 1
return count
class CSVImporter(Importer):
def load(self, file_obj, header=True, **kwargs):
count = 0
reader = csv.reader(file_obj, **kwargs)
if header:
try:
header_keys = next(reader)
except StopIteration:
return count
if self.strict:
header_fields = []
for idx, key in enumerate(header_keys):
if key in self.columns:
header_fields.append((idx, self.columns[key]))
else:
header_fields = list(enumerate(header_keys))
else:
header_fields = list(enumerate(self.model._meta.sorted_fields))
if not header_fields:
return count
for row in reader:
obj = {}
for idx, field in header_fields:
if self.strict:
obj[field.name] = field.python_value(row[idx])
else:
obj[field] = row[idx]
self.table.insert(**obj)
count += 1
return count
class TSVImporter(CSVImporter):
def load(self, file_obj, header=True, **kwargs):
kwargs.setdefault('delimiter', '\t')
return super(TSVImporter, self).load(file_obj, header, **kwargs)