Merge 7e439c7 into 2e3b828

great_expectations/data_asset/file_data_asset.py

@@ -387,7 +387,7 @@ def expect_file_hash_to_equal(self, value, hash_alg='md5', result_format=None,
         return {"success":success}
 
     @DataAsset.expectation(["minsize", "maxsize"])
-    def expect_file_size_to_be_between(self, minsize, maxsize, result_format=None,
+    def expect_file_size_to_be_between(self, minsize=0, maxsize=None, result_format=None,
                                        include_config=False, catch_exceptions=None,
                                        meta=None):
 
@@ -421,31 +421,39 @@ def expect_file_size_to_be_between(self, minsize, maxsize, result_format=None,
         :ref:`include_config`, :ref:`catch_exceptions`, and :ref:`meta`.
         """
 
-        success = False
         try:
             size = os.path.getsize(self._path)
         except OSError:
             raise
 
-        if not isinstance(minsize,int):
+        if not float(minsize).is_integer():
             raise TypeError('minsize must be an integer')
 
-        if not isinstance(maxsize,int):
+        if maxsize is not None and not float(maxsize).is_integer():
             raise TypeError('maxsize must be an integer')
 
         if minsize < 0:
             raise ValueError('minsize must be greater than of equal to 0')
 
-        if maxsize < 0:
+        if maxsize is not None and maxsize < 0:
             raise ValueError('maxsize must be greater than of equal to 0')
 
-        if minsize > maxsize:
+        if maxsize is not None and minsize > maxsize:
             raise ValueError('maxsize must be greater than of equal to minsize')
 
-        if (size >= minsize) and (size <= maxsize):
+        if maxsize is None and size >= minsize:
+            success = True
+        elif (size >= minsize) and (size <= maxsize):
             success = True
+        else: 
+            success = False
 
-        return {"success":success}
+        return {
+            "success": success,
+            "details": {
+                "filesize": size
+            }
+        }
 
     @DataAsset.expectation(["filepath"])
     def expect_file_to_exist(self, filepath=None, result_format=None, include_config=False,