Fix isort, retain some comments

Author: vnlitvinov

asv_bench/benchmarks/io/parsers.py

@@ -1,6 +1,8 @@
+import numpy as np
+
 from pandas._libs.tslibs.parsing import _does_string_look_like_datetime
+
 from pandas.io.parsers import _concat_date_cols
-import numpy as np
 
 
 class DoesStringLookLikeDatetime(object):

pandas/_libs/tslibs/parsing.pyx

@@ -219,6 +219,8 @@ cpdef bint _does_string_look_like_datetime(object date_string):
     if length >= 1:
         first = buf[0]
         if first == b'0':
+            # Strings starting with 0 are more consistent with a
+            # date-like string than a number
             return True
         elif date_string in _not_datelike_strings:
             return False

pandas/io/parsers.py

@@ -14,8 +14,8 @@
 
 import numpy as np
 
-from pandas._libs.lib import _concat_date_cols
 import pandas._libs.lib as lib
+from pandas._libs.lib import _concat_date_cols
 import pandas._libs.ops as libops
 import pandas._libs.parsers as parsers
 from pandas._libs.tslibs import parsing
@@ -3194,13 +3194,9 @@ def converter(*date_cols):
             except Exception:
                 try:
                     return tools.to_datetime(
-                        parsing.try_parse_dates(
-                            _concat_date_cols(
-                                date_cols,
-                                keep_trivial_numbers=True
-                            ),
-                            parser=date_parser,
-                            dayfirst=dayfirst),
+                        parsing.try_parse_dates(_concat_date_cols(date_cols),
+                                                parser=date_parser,
+                                                dayfirst=dayfirst),
                         errors='ignore')
                 except Exception:
                     return generic_parser(date_parser, *date_cols)