pandas read_csv

[Rob Gaddi]

On 11/9/18 6:54 AM, Sharan Basappa wrote:
> are there any requirements about the format of the CSV file when using read_csv from pandas?
> For example, is it necessary that the csv file has to have same number of columns in every line etc.
> 
> I am trying to load a csv file and I get the following error.
> I really don't know what the issue is ...
> Any help is appreciated ...
> 
> ParserErrorTraceback (most recent call last)
> D:\Projects\Initiatives\machine learning\programs\log\log_analysis_1.py in <module>()
>       10
>       11 #data_df = pd.read_csv("BGL_MERGED.log", nrows=100, header=None, delimiter=r'\s"')
> ---> 12 data_df = pd.read_csv("d:\Projects\Initiatives\machine learning\programs\log\BGL_MERGED.log", nrows=100, header=None)
>       13 logger.debug("data frame %s \n", data_df)
>       14 print('Cols %d' %(len(data_df.columns)))
> D:\Users\sharanb\AppData\Local\Enthought\Canopy\edm\envs\User\lib\site-packages\pandas\io\parsers.pyc 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)
>      653                     skip_blank_lines=skip_blank_lines)
>      654
> --> 655         return _read(filepath_or_buffer, kwds)
>      656
>      657     parser_f.__name__ = name
> D:\Users\sharanb\AppData\Local\Enthought\Canopy\edm\envs\User\lib\site-packages\pandas\io\parsers.pyc in _read(filepath_or_buffer, kwds)
>      409
>      410     try:
> --> 411         data = parser.read(nrows)
>      412     finally:
>      413         parser.close()
> D:\Users\sharanb\AppData\Local\Enthought\Canopy\edm\envs\User\lib\site-packages\pandas\io\parsers.pyc in read(self, nrows)
>     1003                 raise ValueError('skipfooter not supported for iteration')
>     1004
> -> 1005         ret = self._engine.read(nrows)
>     1006
>     1007         if self.options.get('as_recarray'):
> D:\Users\sharanb\AppData\Local\Enthought\Canopy\edm\envs\User\lib\site-packages\pandas\io\parsers.pyc in read(self, nrows)
>     1746     def read(self, nrows=None):
>     1747         try:
> -> 1748             data = self._reader.read(nrows)
>     1749         except StopIteration:
>     1750             if self._first_chunk:
> pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader.read (pandas\_libs\parsers.c:10862)()
> pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader._read_low_memory (pandas\_libs\parsers.c:11343)()
> pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader._read_rows (pandas\_libs\parsers.c:11884)()
> pandas/_libs/parsers.pyx in pandas._libs.parsers.TextReader._tokenize_rows (pandas\_libs\parsers.c:11755)()
> pandas/_libs/parsers.pyx in pandas._libs.parsers.raise_parser_error (pandas\_libs\parsers.c:28765)()
> ParserError: Error tokenizing data. C error: Expected 1 fields in line 8, saw 3
> 

Offhand, and as a guess based on nothing, I would speculate that 
something about line 8 of your CSV file differs from lines 1-7.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.