fix: Don't error on empty iterators 1db7277

wireservice · Apr 28, 2024 · 44d1673 · 44d1673
1 parent be4fa7d
commit 44d1673
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Showing 2 changed files with 10 additions and 11 deletions.
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -1,7 +1,7 @@
 1.10.1 - April 27, 2024
 -----------------------
 
--  fix: Version 1.10.0 seeks to the file's beginning, instead of to the original offset.
+-  fix: Version 1.10.0 errors on empty tables and seeks to the file's beginning, instead of to the original offset.
 -  fix: :meth:`.Number.csvify` returns a ``Decimal`` (or ``None``), instead of ``str``. :meth:`.Table.to_csv` with ``quoting=csv.QUOTE_NONNUMERIC`` now works.
 
 1.10.0 - April 27, 2024

diff --git a/agate/table/__init__.py b/agate/table/__init__.py
@@ -78,18 +78,17 @@ def __init__(self, rows, column_names=None, column_types=None, row_names=None, _
         # Validate column names
         if column_names:
             self._column_names = utils.deduplicate(column_names, column_names=True)
-        elif rows:
+        else:
+            rows = iter(rows)
             try:
-                first_row = rows[0]
-            except TypeError:
-                # rows is an iterator.
                 first_row = next(rows)
+            except StopIteration:
+                self._column_names = tuple()
+            else:
                 rows = chain([first_row], rows)
-            self._column_names = tuple(utils.letter_name(i) for i in range(len(first_row)))
-            warnings.warn('Column names not specified. "%s" will be used as names.' % str(self._column_names),
-                          RuntimeWarning, stacklevel=2)
-        else:
-            self._column_names = tuple()
+                self._column_names = tuple(utils.letter_name(i) for i in range(len(first_row)))
+                warnings.warn('Column names not specified. "%s" will be used as names.' % str(self._column_names),
+                              RuntimeWarning, stacklevel=2)
 
         len_column_names = len(self._column_names)
 
@@ -108,7 +107,7 @@ def __init__(self, rows, column_names=None, column_types=None, row_names=None, _
                     raise ValueError('Column types must be instances of DataType.')
 
         if isinstance(column_types, TypeTester):
-            # In case rows is an iterator, in which case need to read it all into memory.
+            # Need to read all rows into memory.
             rows = tuple(rows)
             self._column_types = column_types.run(rows, self._column_names)
         else: