Fixed #373 - Properly detect xlsx format

3 files changed, 7 insertions, 3 deletions

diff --git a/tablib/formats/__init__.py b/tablib/formats/__init__.py
index 418e607..52cf472 100644
--- a/tablib/formats/__init__.py
+++ b/tablib/formats/__init__.py
@@ -17,4 +17,5 @@ from . import _df as df
 from . import _rst as rst
 from . import _jira as jira
 
-available = (json, xls, yaml, csv, dbf, tsv, html, jira, latex, xlsx, ods, df, rst)
+# xlsx before as xls (xlrd) can also read xlsx
+available = (json, xlsx, xls, yaml, csv, dbf, tsv, html, jira, latex, ods, df, rst)
diff --git a/tablib/formats/_json.py b/tablib/formats/_json.py
index a794a3d..009fb3c 100644
--- a/tablib/formats/_json.py
+++ b/tablib/formats/_json.py
@@ -55,5 +55,5 @@ def detect(stream):
     try:
         json.loads(stream)
         return True
-    except ValueError:
+    except (TypeError, ValueError):
         return False
diff --git a/tablib/formats/_xlsx.py b/tablib/formats/_xlsx.py
index 6662a2f..516191c 100644
--- a/tablib/formats/_xlsx.py
+++ b/tablib/formats/_xlsx.py
@@ -22,8 +22,11 @@ extensions = ('xlsx',)
 
 def detect(stream):
     """Returns True if given stream is a readable excel file."""
+    if isinstance(stream, bytes):
+        # load_workbook expects a file-like object.
+        stream = BytesIO(stream)
     try:
-        openpyxl.reader.excel.load_workbook(stream)
+        openpyxl.reader.excel.load_workbook(stream, read_only=True)
         return True
     except openpyxl.shared.exc.InvalidFileException:
         pass