79 lines
2.4 KiB
Python

import numpy as np
from ... import defines
from .base import NumpyColumn
class NumpyStringColumn(NumpyColumn):
null_value = ''
default_encoding = defines.STRINGS_ENCODING
def __init__(self, encoding=default_encoding, **kwargs):
self.encoding = encoding
super(NumpyStringColumn, self).__init__(**kwargs)
def read_items(self, n_items, buf):
return np.array(
buf.read_strings(n_items, encoding=self.encoding), dtype=self.dtype
)
def write_items(self, items, buf):
return buf.write_strings(items.tolist(), encoding=self.encoding)
class NumpyByteStringColumn(NumpyColumn):
null_value = b''
def read_items(self, n_items, buf):
return np.array(buf.read_strings(n_items), dtype=self.dtype)
def write_items(self, items, buf):
return buf.write_strings(items.tolist())
class NumpyFixedString(NumpyStringColumn):
def __init__(self, length, **kwargs):
self.length = length
super(NumpyFixedString, self).__init__(**kwargs)
def read_items(self, n_items, buf):
return np.array(buf.read_fixed_strings(
n_items, self.length, encoding=self.encoding
), dtype=self.dtype)
def write_items(self, items, buf):
return buf.write_fixed_strings(
items.tolist(), self.length, encoding=self.encoding
)
class NumpyByteFixedString(NumpyByteStringColumn):
def __init__(self, length, **kwargs):
self.length = length
super(NumpyByteFixedString, self).__init__(**kwargs)
def read_items(self, n_items, buf):
return np.array(
buf.read_fixed_strings(n_items, self.length), dtype=self.dtype
)
def write_items(self, items, buf):
return buf.write_fixed_strings(items.tolist(), self.length)
def create_string_column(spec, column_options):
client_settings = column_options['context'].client_settings
strings_as_bytes = client_settings['strings_as_bytes']
encoding = client_settings.get(
'strings_encoding', NumpyStringColumn.default_encoding
)
if spec == 'String':
cls = NumpyByteStringColumn if strings_as_bytes else NumpyStringColumn
return cls(encoding=encoding, **column_options)
else:
length = int(spec[12:-1])
cls = NumpyByteFixedString if strings_as_bytes else NumpyFixedString
return cls(length, encoding=encoding, **column_options)