mirror of
https://github.com/kennethreitz/tablib.git
synced 2026-06-05 23:10:17 +00:00
Kenneth Reitz
327 lines
6.4 KiB
Python
327 lines
6.4 KiB
Python
# -*- coding: utf-8 -*-
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""" Tablib - Core Library.
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"""
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from tablib.formats import FORMATS as formats
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__title__ = 'tablib'
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__version__ = '0.8.1'
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__build__ = 0x000801
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__author__ = 'Kenneth Reitz'
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__license__ = 'MIT'
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__copyright__ = 'Copyright 2010 Kenneth Reitz'
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class Dataset(object):
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"""Epic Tabular-Dataset object. """
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def __init__(self, *args, **kwargs):
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self._data = list(args)
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self.__headers = None
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# ('title', index) tuples
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self._seperators = []
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try:
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self.headers = kwargs['headers']
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except KeyError:
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self.headers = None
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try:
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self.title = kwargs['title']
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except KeyError:
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self.title = None
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self._register_formats()
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def __len__(self):
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return self.height
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def __getitem__(self, key):
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if isinstance(key, basestring):
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if key in self.headers:
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pos = self.headers.index(key) # get 'key' index from each data
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return [row[pos] for row in self._data]
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else:
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raise KeyError
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else:
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return self._data[key]
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def __setitem__(self, key, value):
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self._validate(value)
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self._data[key] = tuple(value)
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def __delitem__(self, key):
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del self._data[key]
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def __repr__(self):
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try:
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return '<%s dataset>' % (self.title.lower())
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except AttributeError:
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return '<dataset object>'
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@classmethod
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def _register_formats(cls):
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"""Adds format properties."""
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for fmt in formats:
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try:
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try:
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setattr(cls, fmt.title, property(fmt.export_set, fmt.import_set))
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except AttributeError:
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setattr(cls, fmt.title, property(fmt.export_set))
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except AttributeError:
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pass
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def _validate(self, row=None, col=None, safety=False):
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"""Assures size of every row in dataset is of proper proportions."""
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if row:
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is_valid = (len(row) == self.width) if self.width else True
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elif col:
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if self.headers:
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is_valid = (len(col) - 1) == self.height
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else:
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is_valid = (len(col) == self.height) if self.height else True
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else:
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is_valid = all((len(x)== self.width for x in self._data))
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if is_valid:
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return True
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else:
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if not safety:
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raise InvalidDimensions
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return False
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def _package(self, dicts=True):
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"""Packages Dataset into lists of dictionaries for transmission."""
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if self.headers:
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if dicts:
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data = [dict(zip(self.headers, data_row)) for data_row in self ._data]
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else:
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data = [list(self.headers)] + list(self._data)
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else:
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data = [list(row) for row in self._data]
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return data
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@property
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def height(self):
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"""Returns the height of the Dataset."""
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return len(self._data)
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@property
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def width(self):
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"""Returns the width of the Dataset."""
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try:
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return len(self._data[0])
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except IndexError:
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try:
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return len(self.headers)
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except TypeError:
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return 0
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@property
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def headers(self):
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"""Headers property."""
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return self.__headers
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@headers.setter
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def headers(self, collection):
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"""Validating headers setter."""
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self._validate(collection)
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if collection:
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try:
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self.__headers = list(collection)
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except TypeError:
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raise TypeError
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else:
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self.__headers = None
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@property
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def dict(self):
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"""Returns python dict of Dataset."""
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return self._package()
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@dict.setter
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def dict(self, pickle):
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"""Returns python dict of Dataset."""
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if not len(pickle):
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return
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if isinstance(pickle[0], list):
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for row in pickle:
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self.append(row)
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elif isinstance(pickle[0], dict):
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self.headers = pickle[0].keys()
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for row in pickle:
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self.append(row.values())
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else:
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raise UnsupportedFormat
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def append(self, row=None, col=None):
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"""Adds a row to the end of Dataset"""
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if row:
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self._validate(row)
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self._data.append(tuple(row))
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elif col:
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self._validate(col=col)
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if self.headers:
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# pop the first item off, add to headers
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self.headers.append(col[0])
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col = col[1:]
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if self.height and self.width:
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for i, row in enumerate(self._data):
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_row = list(row)
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_row.append(col[i])
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self._data[i] = tuple(_row)
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else:
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self._data = [tuple([row]) for row in col]
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def insert_seperator(self, index, text='-'):
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"""Adds a seperator to Dataset at given index."""
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if self.height >= index:
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sep = (index, text)
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self._seperators.append(sep)
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else:
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raise InvalidDimensions
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def append_seperator(self, text='-'):
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"""Adds a seperator to Dataset."""
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index = self.height if self.headers else (self.height - 1)
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self.insert_seperator(index, text)
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def insert(self, i, row=None, col=None):
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"""Inserts a row at given position in Dataset"""
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if row:
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self._validate(row)
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self._data.insert(i, tuple(row))
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elif col:
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pass
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def wipe(self):
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"""Erases all data from Dataset."""
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self._data = list()
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self.__headers = None
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class Databook(object):
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"""A book of Dataset objects.
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Currently, this exists only for XLS workbook support.
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"""
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def __init__(self, sets=[]):
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self._datasets = sets
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self._register_formats()
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def __repr__(self):
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try:
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return '<%s databook>' % (self.title.lower())
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except AttributeError:
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return '<databook object>'
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def wipe(self):
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"""Wipe book clean."""
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self._datasets = []
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@classmethod
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def _register_formats(cls):
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"""Adds format properties."""
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for fmt in formats:
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try:
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try:
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setattr(cls, fmt.title, property(fmt.export_book, fmt.import_book))
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except AttributeError:
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setattr(cls, fmt.title, property(fmt.export_book))
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except AttributeError:
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pass
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def add_sheet(self, dataset):
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"""Adds given dataset."""
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if type(dataset) is Dataset:
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self._datasets.append(dataset)
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else:
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raise InvalidDatasetType
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def _package(self):
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"""Packages Databook for delivery."""
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collector = []
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for dset in self._datasets:
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collector.append(dict(
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title = dset.title,
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data = dset.dict
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))
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return collector
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@property
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def size(self):
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"""The number of the Datasets within DataBook."""
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return len(self._datasets)
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def detect(stream):
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"""Return (format, stream) of given stream."""
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for fmt in formats:
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try:
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if fmt.detect(stream):
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return (fmt, stream)
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except AttributeError:
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pass
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return (None, stream)
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def import_set(stream):
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"""Return dataset of given stream."""
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(format, stream) = detect(stream)
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try:
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data = Dataset()
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format.import_set(data, stream)
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return data
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except AttributeError, e:
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return None
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class InvalidDatasetType(Exception):
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"Only Datasets can be added to a DataBook"
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class InvalidDimensions(Exception):
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"Invalid size"
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class UnsupportedFormat(NotImplementedError):
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"Format is not supported"
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