Merge with @jreback's pandas-dev#5422

Author: jreback

pandas/io/pytables.py

@@ -225,11 +225,6 @@ def _tables():
     return _table_mod
 
 
-def h5_open(path, mode):
-    tables = _tables()
-    return tables.openFile(path, mode)
-
-
 @contextmanager
 def get_store(path, **kwargs):
     """
@@ -475,6 +470,8 @@ def open(self, mode='a'):
         mode : {'a', 'w', 'r', 'r+'}, default 'a'
             See HDFStore docstring or tables.openFile for info about modes
         """
+        tables = _tables()
+
         if self._mode != mode:
 
             # if we are chaning a write mode to read, ok
@@ -501,13 +498,20 @@ def open(self, mode='a'):
                                               fletcher32=self._fletcher32)
 
         try:
-            self._handle = h5_open(self._path, self._mode)
-        except IOError as e:  # pragma: no cover
+            self._handle = tables.openFile(self._path, self._mode)
+        except (IOError) as e:  # pragma: no cover
             if 'can not be written' in str(e):
                 print('Opening %s in read-only mode' % self._path)
-                self._handle = h5_open(self._path, 'r')
+                self._handle = tables.openFile(self._path, 'r')
             else:
                 raise
+        except (Exception) as e:
+
+            # trying to read from a non-existant file causes an error which
+            # is not part of IOError, make it one
+            if self._mode == 'r' and 'Unable to open/create file' in str(e):
+                raise IOError(str(e))
+            raise
 
     def close(self):
         """

pandas/io/tests/test_pytables.py

@@ -3,6 +3,7 @@
 import sys
 import os
 import warnings
+import tempfile
 from contextlib import contextmanager
 
 import datetime
@@ -57,6 +58,11 @@ def safe_close(store):
 @contextmanager
 def ensure_clean(path, mode='a', complevel=None, complib=None,
               fletcher32=False):
+
+    # put in the temporary path if we don't have one already
+    if not len(os.path.dirname(path)):
+        path = tempfile.mkstemp(suffix=path)[1]
+
     store = HDFStore(path, mode=mode, complevel=complevel,
                      complib=complib, fletcher32=False)
     try:
@@ -192,17 +198,22 @@ def test_api(self):
 
         with ensure_clean(self.path) as store:
 
+            path = store._path
             df = tm.makeDataFrame()
+
+            _maybe_remove(store,'df')
             store.append('df',df.iloc[:10],append=True,format='table')
             store.append('df',df.iloc[10:],append=True,format='table')
             assert_frame_equal(read_hdf(path,'df'),df)
 
             # append to False
+            _maybe_remove(store,'df')
             store.append('df',df.iloc[:10],append=False,format='table')
             store.append('df',df.iloc[10:],append=True,format='table')
             assert_frame_equal(read_hdf(path,'df'),df)
 
             # formats
+            _maybe_remove(store,'df')
             store.append('df',df.iloc[:10],append=False,format='table')
             store.append('df',df.iloc[10:],append=True,format='table')
             assert_frame_equal(read_hdf(path,'df'),df)
@@ -373,7 +384,7 @@ def check(mode):
             with tm.ensure_clean(self.path, make_tempfile=False) as path:
 
                 # constructor
-                if mode in ['r','r+']:
+                if mode in ['r']:
                     self.assertRaises(IOError, HDFStore, path, mode=mode)
 
                 else:
@@ -384,7 +395,7 @@ def check(mode):
             with tm.ensure_clean(self.path, make_tempfile=False) as path:
 
                 # context
-                if mode in ['r','r+']:
+                if mode in ['r']:
                     def f():
                         with get_store(path,mode=mode) as store:
                             pass
@@ -396,7 +407,7 @@ def f():
             with tm.ensure_clean(self.path, make_tempfile=False) as path:
 
                 # conv write
-                if mode in ['r','r+']:
+                if mode in ['r']:
                     self.assertRaises(IOError, df.to_hdf, path, 'df', mode=mode)
                     df.to_hdf(path,'df',mode='w')
                 else:

pandas/util/testing.py

@@ -314,7 +314,7 @@ def ensure_clean(filename=None, return_filelike=False, make_tempfile=True):
     filename : str (optional)
         if None, creates a temporary file which is then removed when out of
         scope. if passed, creates temporary file with filename as ending.
-    return_filelike: bool (default False)
+    return_filelike : bool (default False)
         if True, returns a file-like which is *always* cleaned. Necessary for
         savefig and other functions which want to append extensions. Ignores
         filename if True.
@@ -332,15 +332,14 @@ def ensure_clean(filename=None, return_filelike=False, make_tempfile=True):
             f.close()
 
     else:
-        # if we are not passed a filename, generate a temporary
-        if make_tempfile or not filename:
-            filename = tempfile.mkstemp(suffix=filename)[1]
-
         try:
+            # if we are not passed a filename, generate a temporary
+            if make_tempfile or not filename:
+                filename = tempfile.mkstemp(suffix=filename)[1]
             yield filename
         finally:
             try:
-                if os.path.exists(filename):
+                if filename and os.path.exists(filename):
                     os.remove(filename)
             except Exception as e:
                 print("Exception on removing file: %s" % e)