Closed
Description
This is probably similar to #14792, but still happens with 0.23.3 (a friend even tested it with 1.0.3).
Testcase
import io
s = """A,B,\n1,2"""
pd.read_csv(io.StringIO(s), parse_dates=["B"], names=["B"])raises:
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-146-082b3d7afa0a> in <module>()
1 import io
2 s = """A,B,\n1,2"""
----> 3 pd.read_csv(io.StringIO(s), parse_dates=["B"], names=["B"])
/usr/lib/python3/dist-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, doublequote, delim_whitespace, low_memory, memory_map, float_precision)
676 skip_blank_lines=skip_blank_lines)
677
--> 678 return _read(filepath_or_buffer, kwds)
679
680 parser_f.__name__ = name
/usr/lib/python3/dist-packages/pandas/io/parsers.py in _read(filepath_or_buffer, kwds)
444
445 try:
--> 446 data = parser.read(nrows)
447 finally:
448 parser.close()
/usr/lib/python3/dist-packages/pandas/io/parsers.py in read(self, nrows)
1034 raise ValueError('skipfooter not supported for iteration')
1035
-> 1036 ret = self._engine.read(nrows)
1037
1038 # May alter columns / col_dict
/usr/lib/python3/dist-packages/pandas/io/parsers.py in read(self, nrows)
1887
1888 values = self._maybe_parse_dates(values, i,
-> 1889 try_parse_dates=True)
1890 arrays.append(values)
1891
/usr/lib/python3/dist-packages/pandas/io/parsers.py in _maybe_parse_dates(self, values, index, try_parse_dates)
1946
1947 def _maybe_parse_dates(self, values, index, try_parse_dates=True):
-> 1948 if try_parse_dates and self._should_parse_dates(index):
1949 values = self._date_conv(values)
1950 return values
/usr/lib/python3/dist-packages/pandas/io/parsers.py in _should_parse_dates(self, i)
1319 else:
1320 name = None
-> 1321 j = self.index_col[i]
1322
1323 if is_scalar(self.parse_dates):
TypeError: 'NoneType' object is not subscriptable
Notes
This does not happen with engine="python" (you only get a ParseError there).