fix raising FileNotFound when reading with plugins

obspy/core/inventory/inventory.py

@@ -13,9 +13,7 @@
                         unicode_literals)
 from future.builtins import *  # NOQA
 from future.utils import python_2_unicode_compatible, native_str
-from future.utils import PY2
 
-import builtins
 import copy
 import fnmatch
 import os
@@ -39,10 +37,6 @@
 SOFTWARE_URI = "https://www.obspy.org"
 
 
-if PY2:
-    FileNotFoundError = getattr(builtins, 'IOError')
-
-
 def _create_example_inventory():
     """
     Create an example inventory.
@@ -100,10 +94,6 @@ def read_inventory(path_or_file_object=None, format=None, *args, **kwargs):
         with NamedTemporaryFile(suffix=sanitize_filename(suffix)) as fh:
             download_to_file(url=path_or_file_object, filename_or_buffer=fh)
             return read_inventory(fh.name, format=format)
-    if not os.path.exists(path_or_file_object):
-        msg = "[Errno 2] No such file or directory: '{}'".format(
-            path_or_file_object)
-        raise FileNotFoundError(msg)
     return _read_from_plugin("inventory", path_or_file_object,
                              format=format, *args, **kwargs)[0]
 

obspy/core/util/base.py

@@ -11,7 +11,9 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 from future.builtins import *  # NOQA
+from future.utils import PY2
 
+import builtins
 import doctest
 import inspect
 import io
@@ -357,10 +359,19 @@ def get_dependency_version(package_name, raw_string=False):
 CARTOPY_VERSION = get_dependency_version('cartopy')
 
 
+if PY2:
+    FileNotFoundError = getattr(builtins, 'IOError')
+
+
 def _read_from_plugin(plugin_type, filename, format=None, **kwargs):
     """
     Reads a single file from a plug-in's readFormat function.
     """
+    if isinstance(filename, (str, native_str)):
+        if not os.path.exists(filename):
+            msg = "[Errno 2] No such file or directory: '{}'".format(
+                filename)
+            raise FileNotFoundError(msg)
     eps = ENTRY_POINTS[plugin_type]
     # get format entry point
     format_ep = None