def get_csv_row_writer(stream, dialect=csv.excel, encoding="utf-8", **kwargs):
"""
Create a csv, encoding from unicode, row writer.
Use returned callable to write rows of unicode data
to a stream, such as a file opened in write mode,
in utf-8(or another) encoding.
::
my_row_data = [
[u'one', u'two'],
[u'three', u'four'],
]
with open('myfile.csv', 'wt') as myfile:
unicode_row_writer = get_unicode_row_writer(myfile)
for row in my_row_data:
unicode_row_writer(row)
"""
if is_py3():
writer = csv.writer(stream, dialect=dialect, **kwargs)
return writer.writerow
else:
queue = StringIO()
writer = csv.writer(queue, dialect=dialect, **kwargs)
encoder = codecs.getincrementalencoder(encoding)()
return partial(_encode_write_row, stream, queue, writer, encoder)
def test_default_reader(self):
"""
Ensure results have given items_func, collect_first, applied to them.
"""
import karld
from karld.run_together import distribute_multi_run_to_runners
input_path = os.path.join(os.path.dirname(__file__),
"test_data",
"things_kinds")
test_results = distribute_multi_run_to_runners(
collect_first,
in_dir=input_path,
batch_size=10,
filter_func=karld.io.is_file_csv)
list_results = list(test_results)
self.assertEqual(len(list_results[0]), 10)
self.assertEqual(len(list_results[1]), 5)
if is_py3():
self.assertEqual(
sorted(chain.from_iterable(list_results)),
[87, 97, 99, 99, 99, 100, 105,
109, 111, 112, 112, 114, 116, 116, 116]
)
else:
self.assertEqual(
sorted(chain.from_iterable(list_results)),
['W', 'a', 'c', 'c', 'c', 'd',
'i', 'm', 'o', 'p', 'p', 'r', 't', 't', 't'],
)
def split_file_output(name, data, out_dir, max_lines=1100,
buffering=FILE_BUFFER_SIZE):
"""
Split an iterable lines into groups and write each to
a shard.
:param name: Each shard will use this in it's name.
:type name: str
:param data: Iterable of data to write.
:type data: iter
:param out_dir: Path to directory to write the shards.
:type out_dir: str
:param max_lines: Max number of lines per shard.
:type max_lines: int
:param buffering: number of bytes to buffer files
:type buffering: int
"""
batches = i_batch(max_lines, data)
if is_py3():
join_str = b''
else:
join_str = ''
index = count()
for group in batches:
file_path = os.path.join(out_dir,
"{0}_{1}".format(next(index), name))
with open(file_path, 'wb', buffering=buffering) as shard_file:
shard_file.write(join_str.join(group))
def i_get_csv_data(file_name, *args, **kwargs):
"""A generator for reading a csv file.
"""
buffering = kwargs.get('buffering', FILE_BUFFER_SIZE)
read_file_kwargs = dict(buffering=buffering)
if is_py3():
read_file_kwargs.update(dict(binary=False))
read_file_kwargs.update(dict(py3_csv_read=True))
data = i_read_buffered_file(file_name, **read_file_kwargs)
for row in csv_reader(data, *args, **kwargs):
yield row
def i_read_buffered_file(file_name, buffering=FILE_BUFFER_SIZE, binary=True,
py3_csv_read=False, encoding='utf-8'):
"""
Generator of lines of a file name, with buffering for
speed.
"""
kwargs = dict(buffering=buffering, )
if is_py3():
if not binary:
kwargs.update(dict(encoding=encoding))
if py3_csv_read:
kwargs.update(dict(newline=''))
with open(file_name, 'r' + ('b' if binary else 't'), **kwargs) as stream:
for line in stream:
yield line
def merge(*iterables, **kwargs):
"""Merge multiple sorted inputs into a single sorted output.
Similar to sorted(itertools.chain(\*iterables)) but returns a generator,
does not pull the data into memory all at once, and assumes that each of
the input streams is already sorted (smallest to largest).
>>> list(merge([[2,1],[2,3],[2,5],[2,7]],
[[2,0],[2,2],[2,4],[2,8]],
[[2,5],[2,10],[2,15],[2,20]],
[], [[2,25]]), key=itemgetter(-1))
[0, 1, 2, 3, 4, 5, 5, 7, 8, 10, 15, 20, 25]
"""
key = kwargs.get('key')
_heappop, _heapreplace, _StopIteration = heapq.heappop, heapq.heapreplace, StopIteration
if is_py3():
next_method = attrgetter('__next__')
else:
next_method = attrgetter('next')
h = []
h_append = h.append
key_is_None = key is None
for itnum, it in enumerate(map(iter, iterables)):
try:
nnext = next_method(it)
v = nnext()
h_append([v if key_is_None else key(v), itnum, v, nnext])
except _StopIteration:
pass
heapq.heapify(h)
while 1:
try:
while 1:
# raises IndexError when h is empty
k, itnum, v, nnext = s = h[0]
yield v
v = nnext() # raises StopIteration when exhausted
s[0] = v if key_is_None else key(v)
s[2] = v
_heapreplace(h, s) # restore heap condition
except _StopIteration:
_heappop(h) # remove empty iterator
except IndexError:
return
def test_csv_file_to_file_integration(self):
"""
Ensure
"""
from karld.loadump import file_path_and_name
from karld.run_together import csv_file_to_file
out_dir = os.path.join(tempfile.gettempdir(),
"karld_test_csv_file_to_file")
prefix = str(datetime.now())
out_filename = "data_0.csv"
input_path = os.path.join(os.path.dirname(__file__),
"test_data",
"things_kinds")
def combiner(items):
return items
expected_file = os.path.join(out_dir,
"{}{}".format(prefix, out_filename))
if os.path.exists(expected_file):
os.remove(expected_file)
csv_file_to_file(combiner, prefix, out_dir, file_path_and_name(input_path, "data_0.csv"))
self.assertTrue(os.path.exists(expected_file))
expected_data = (b'mushroom,fungus\ntomato,fruit\ntopaz,mineral\n'
b'iron,metal\ndr\xc3\xb3\xc5\xbck\xc4\x85,'
b'utf-8 sample\napple,fruit\ncheese,dairy\n'
b'peach,fruit\ncelery,vegetable\n'.decode('utf-8'))
if is_py3():
with open(expected_file, 'rt') as result_file:
contents = result_file.read()
self.assertEqual(expected_data, contents)
else:
with open(expected_file, 'r') as result_file:
contents = result_file.read()
self.assertEqual(expected_data.splitlines(),
contents.decode('utf-8').splitlines())
if os.path.exists(expected_file):
os.remove(expected_file)
def i_get_unicode_lines(file_name, encoding='utf-8', **kwargs):
"""
A generator for reading a text file as unicode lines.
:param file_name: Path to file.
:param encoding: Encoding of the file.
:yields: Lines of the file decoded from encoding to unicode.
"""
buffering = kwargs.get('buffering', FILE_BUFFER_SIZE)
read_file_kwargs = dict(buffering=buffering, encoding=encoding)
if is_py3():
stream = i_read_buffered_text_file(file_name, **read_file_kwargs)
for line in stream:
yield line
else:
stream = i_read_buffered_binary_file(file_name, **read_file_kwargs)
for line in codecs.iterdecode(stream, encoding, **kwargs):
yield line
def main():
"""
From a source of data, shard it to csv files.
"""
import pathlib
if karld.is_py3():
third = chr
else:
third = unichr
# Your data source
items = ((x, x + 1, third(x + 10)) for x in range(2000))
out_dir = pathlib.Path('shard_out_json')
karld.io.ensure_dir(str(out_dir))
karld.io.split_file_output_json('big_data.json', items, str(out_dir))
def csv_unicode_reader(unicode_csv_data, dialect=csv.excel, **kwargs):
"""
Generator the reads serialized unicode csv data.
Use this if you have a stream of data
in unicode and you want to access the rows
of the data as sequences encoded as unicode.
Unicode in, unicode out.
:param unicode_csv_data: An iterable of unicode strings.
:param dialect: csv dialect
"""
if is_py3():
return csv.reader(unicode_csv_data, dialect=dialect, **kwargs)
else:
encoded_utf8_data = imap(encode_utf8, unicode_csv_data)
reader = csv.reader(encoded_utf8_data, dialect=dialect, **kwargs)
return imap(map_decode_utf8_to_unicode, reader)
def csv_reader(csv_data, dialect=csv.excel, encoding="utf-8", **kwargs):
"""
Csv row generator that re-encodes to
unicode from csv data with a given encoding.
Utf-8 data in, unicode out. You may specify a different
encoding of the incoming data.
:param csv_data: An iterable of str of the specified encoding.
:param dialect: csv dialect
:param encoding: The encoding of the given data.
"""
if is_py3():
return csv.reader(csv_data, dialect=csv.excel, **kwargs)
reader = csv.reader(
_utf8_iter_recoder(csv_data, encoding),
dialect=dialect, **kwargs
)
return imap(map_decode_utf8_to_unicode, reader)
def write_as_csv(items, file_name, append=False,
line_buffer_size=None, buffering=FILE_BUFFER_SIZE,
get_csv_row_writer=get_csv_row_writer):
"""
Writes out items to a csv file in groups.
:param items: An iterable collection of collections.
:param file_name: path to the output file.
:param append: whether to append or overwrite the file.
:param line_buffer_size: number of lines to write at a time.
:param buffering: number of bytes to buffer files
:type buffering: int
:param get_csv_row_writer: callable that returns a csv row writer function,
customize this for non-default options:
`custom_writer = partial(get_csv_row_writer, delimiter="|");`
`write_as_csv(items, 'my_out_file', get_csv_row_writer=custom_writer)`
"""
if line_buffer_size is None:
line_buffer_size = LINE_BUFFER_SIZE
if append:
mode = 'a'
else:
mode = 'w'
kwargs = dict(buffering=buffering)
if is_py3():
mode += 't'
kwargs.update(dict(newline=''))
else:
mode += 'b'
with open(file_name, mode, **kwargs) as csv_file:
write_row = get_csv_row_writer(csv_file)
batches = i_batch(line_buffer_size, items)
for batch in batches:
for row in batch:
write_row(row)
from operator import methodcaller
try:
from itertools import imap
except ImportError:
imap = map
import logging
import re
from collections import OrderedDict
from karld import is_py3
if is_py3():
unicode = str
NOT_NUMBER_REG = re.compile(r'\D')
str_strip = methodcaller('strip')
def apply_conversion_map(conversion_map, entity):
"""
returns tuple of conversions
"""
return tuple([conversion(entity) for key, conversion in conversion_map])
