BUG: add fix for opening zero observation dta files

Author: bquistorff

doc/source/v0.14.1.txt

@@ -123,3 +123,4 @@ Bug Fixes
 - Bug where a string column name assignment to a ``DataFrame`` with a
   ``Float64Index`` raised a ``TypeError`` during a call to ``np.isnan``
   (:issue:`7366`).
+- Bug in ``StataReader.data`` where reading a 0-observation dta failed (:issue:`7369`)

pandas/io/stata.py

@@ -852,7 +852,10 @@ def data(self, convert_dates=True, convert_categoricals=True, index=None):
         if convert_categoricals:
             self._read_value_labels()
 
-        data = DataFrame(data, columns=self.varlist, index=index)
+        if len(data)==0:
+            data = DataFrame(columns=self.varlist, index=index)
+        else:
+            data = DataFrame(data, columns=self.varlist, index=index)
 
         cols_ = np.where(self.dtyplist)[0]
         for i in cols_:

pandas/io/tests/test_stata.py

@@ -72,6 +72,14 @@ def read_dta(self, file):
     def read_csv(self, file):
         return read_csv(file, parse_dates=True)
 
+    def test_read_empty_dta(self):
+        empty_ds = DataFrame(columns=['unit'])
+        # GH 7369, make sure can read a 0-obs dta file
+        with tm.ensure_clean() as path:
+            empty_ds.to_stata(path,write_index=False)
+            empty_ds2 = read_stata(path)
+            tm.assert_frame_equal(empty_ds, empty_ds2)
+
     def test_read_dta1(self):
         reader_114 = StataReader(self.dta1_114)
         parsed_114 = reader_114.data()