new version

.gitignore

@@ -3,6 +3,7 @@
 *.egg
 dist/*
 .tox/*
+.vscode/*
 build/*
 .DS_Store
 .watchr

dataset/table.py

@@ -384,7 +384,7 @@ class Table(object):
             return True
         for column in columns:
             if not self.has_column(column):
-                raise DatasetException("Column does not exist: %s" % column)
+                return False
         indexes = self.db.inspect.get_indexes(self.name, schema=self.db.schema)
         for index in indexes:
             if columns == set(index.get('column_names', [])):
@@ -405,6 +405,10 @@ class Table(object):
             if not self.exists:
                 raise DatasetException("Table has not been created yet.")
 
+            for column in columns:
+                if not self.has_column(column):
+                    return
+
             if not self.has_index(columns):
                 self._threading_warn()
                 name = name or index_name(self.name, columns)

dataset/util.py

@@ -1,12 +1,7 @@
-try:
-    from urlparse import urlparse
-except ImportError:
-    from urllib.parse import urlparse
-
-from collections import OrderedDict, Sequence
+import six
 from hashlib import sha1
-
-from six import string_types
+from collections import OrderedDict, Sequence
+from six.moves.urllib.parse import urlparse
 
 
 QUERY_STEP = 1000
@@ -60,9 +55,16 @@ class ResultIter(object):
 
 def normalize_column_name(name):
     """Check if a string is a reasonable thing to use as a column name."""
-    if not isinstance(name, string_types):
+    if not isinstance(name, six.string_types):
         raise ValueError('%r is not a valid column name.' % name)
-    name = name.strip()
+
+    # limit to 63 characters
+    name = name.strip()[:63]
+    # column names can be 63 *bytes* max in postgresql
+    if isinstance(name, six.text_type):
+        while len(name.encode('utf-8')) >= 64:
+            name = name[:len(name) - 1]
+
     if not len(name) or '.' in name or '-' in name:
         raise ValueError('%r is not a valid column name.' % name)
     return name
@@ -70,9 +72,9 @@ def normalize_column_name(name):
 
 def normalize_table_name(name):
     """Check if the table name is obviously invalid."""
-    if not isinstance(name, string_types):
+    if not isinstance(name, six.string_types):
         raise ValueError("Invalid table name: %r" % name)
-    name = name.strip()
+    name = name.strip()[:63]
     if not len(name):
         raise ValueError("Invalid table name: %r" % name)
     return name
@@ -98,6 +100,6 @@ def ensure_tuple(obj):
     """Try and make the given argument into a tuple."""
     if obj is None:
         return tuple()
-    if isinstance(obj, Sequence) and not isinstance(obj, string_types):
+    if isinstance(obj, Sequence) and not isinstance(obj, six.string_types):
         return tuple(obj)
     return obj,

setup.py

@@ -3,7 +3,7 @@ from setuptools import setup, find_packages
 
 setup(
     name='dataset',
-    version='1.0.2',
+    version='1.0.3',
     description="Toolkit for Python-based database access.",
     long_description="",
     classifiers=[