from pyexcel_io.sheet import NamedContent
from pyexcel._compact import OrderedDict, SheetIterator
[docs]class SheetStream(NamedContent):
"""
Memory efficient sheet representation
This class wraps around the data read from pyexcel-io.
Comparing with :class:`pyexcel.Sheet`, the instance of
this class does not load all data into memory. Hence
it performs better when dealing with big data.
If you would like to do custom rendering for each row
of the two dimensional data, you would need to
pass a row formatting/rendering function to the parameter
"renderer" of pyexcel's signature functions.
"""
[docs] def __init__(self, name, payload):
NamedContent.__init__(self, name, payload)
self.colnames = []
def to_array(self):
"""
Simply return the generator
"""
return self.payload
[docs]class BookStream(object):
"""
Memory efficient book representation
Comparing with :class:`pyexcel.Book`, the instace of
this class uses :class:`pyexcel.generators.SheetStream` as
its internal repesentation of sheet objects. Because `SheetStream`
does not read data into memory, it is memory efficient.
"""
[docs] def __init__(self, sheets=None, filename="memory", path=None):
"""Book constructor
Selecting a specific book according to filename extension
:param OrderedDict/dict sheets: a dictionary of data
:param str filename: the physical file
:param str path: the relative path or absolute path
:param set keywords: additional parameters to be passed on
"""
self.path = path
self.filename = filename
self.name_array = []
if sheets:
self.load_from_sheets(sheets)
else:
self.sheets = {}
def load_from_sheets(self, sheets):
"""Load content from existing sheets
:param dict sheets: a dictionary of sheets. Each sheet is
a list of lists
"""
if sheets is None:
return
self.sheets = OrderedDict()
keys = sheets.keys()
if not isinstance(sheets, OrderedDict):
# if the end user does not care about the order
# we put alphatical order
keys = sorted(keys)
for name in keys:
sheet = SheetStream(name, sheets[name])
# this sheets keep sheet order
self.sheets.update({name: sheet})
# this provide the convenience of access the sheet
self.__dict__[name] = sheet
self.name_array = list(self.sheets.keys())
def to_dict(self):
"""
Get book data structure as a dictionary
"""
the_dict = OrderedDict()
for sheet in self:
the_dict.update({sheet.name: sheet.payload})
return the_dict
def __iter__(self):
return SheetIterator(self)
def number_of_sheets(self):
"""Return the number of sheets"""
return len(self.name_array)
def __getitem__(self, index):
if index < len(self.name_array):
sheet_name = self.name_array[index]
return self.sheets[sheet_name]