我以前用熊猫来读取和处理数据,有一些记忆问题。我可以读一个大文件:
import pandas as pd
df = pd.read_csv('mydata.csv.gz', sep=';')
但是,在对Dask执行相同操作时,我得到一个错误:
import dask.dataframe as dd
df_base = dd.read_csv('CoilsSampleFiltered.csv.gz', sep=';')
回溯:
UnicodeDecodeError Traceback (most recent call last)
<ipython-input-7-abc513f2a657> in <module>()
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\dask\dataframe\io\csv.py in read(urlpath, blocksize, collection, lineterminator, compression, sample, enforce, assume_missing, storage_options, **kwargs)
424 enforce=enforce, assume_missing=assume_missing,
425 storage_options=storage_options,
427 read.__doc__ = READ_DOC_TEMPLATE.format(reader=reader_name,
428 file_type=file_type)
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\dask\dataframe\io\csv.py in read_pandas(reader, urlpath, blocksize, collection, lineterminator, compression, sample, enforce, assume_missing, storage_options, **kwargs)
324
325 # Use sample to infer dtypes
327
328 specified_dtypes = kwargs.get('dtype', {})
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\parsers.py in parser_f(filepath_or_buffer, sep, delimiter, header, names, index_col, usecols, squeeze, prefix, mangle_dupe_cols, dtype, engine, converters, true_values, false_values, skipinitialspace, skiprows, nrows, na_values, keep_default_na, na_filter, verbose, skip_blank_lines, parse_dates, infer_datetime_format, keep_date_col, date_parser, dayfirst, iterator, chunksize, compression, thousands, decimal, lineterminator, quotechar, quoting, escapechar, comment, encoding, dialect, tupleize_cols, error_bad_lines, warn_bad_lines, skipfooter, skip_footer, doublequote, delim_whitespace, as_recarray, compact_ints, use_unsigned, low_memory, buffer_lines, memory_map, float_precision)
707 skip_blank_lines=skip_blank_lines)
708
710
711 parser_f.__name__ = name
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\parsers.py in _read(filepath_or_buffer, kwds)
447
448 # Create the parser.
450
451 if chunksize or iterator:
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\parsers.py in __init__(self, f, engine, **kwds)
816 self.options['has_index_names'] = kwds['has_index_names']
817
819
820 def close(self):
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\parsers.py in _make_engine(self, engine)
1047 def _make_engine(self, engine='c'):
1048 if engine == 'c':
-> 1049 self._engine = CParserWrapper(self.f, **self.options)
1050 else:
1051 if engine == 'python':
~\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\parsers.py in __init__(self, src, **kwds)
1693 kwds['allow_leading_cols'] = self.index_col is not False
1694
-> 1695 self._reader = parsers.TextReader(src, **kwds)
1696
1697 # XXX
pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader.__cinit__()
pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader._get_header()
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x8b in position 1: invalid start byte
我想弄清楚是什么问题。文件是由R编写的,它默认使用utf-8。