refactor flatten function. move to utils.py

Author: manu-chroma

schema_salad/flatten.py

@@ -12,8 +12,7 @@
 from StringIO import StringIO
 
 from . import validate
-from schema_salad.utils import aslist
-from .flatten import flatten
+from schema_salad.utils import aslist, flatten
 from .sourceline import SourceLine, add_lc_filename, relname
 
 import requests

schema_salad/ref_resolver.py

@@ -1,6 +1,6 @@
 import avro
 import copy
-from schema_salad.utils import add_dictlist, aslist
+from schema_salad.utils import add_dictlist, aslist, flatten
 import sys
 import pprint
 from pkg_resources import resource_stream
@@ -15,7 +15,6 @@
 from avro.schema import Names, SchemaParseException
 from . import ref_resolver
 from .ref_resolver import Loader, DocumentType
-from .flatten import flatten
 import logging
 from . import jsonld_context
 from .sourceline import SourceLine, strip_dup_lineno, add_lc_filename, bullets, relname

schema_salad/schema.py

@@ -16,3 +16,26 @@ def aslist(l):  # type: (Any) -> List
         return l
     else:
         return [l]
+
+# http://rightfootin.blogspot.com/2006/09/more-on-python-flatten.html
+
+def flatten(l, ltypes=(list, tuple)):
+    # type: (Any, Any) -> Any
+    if l is None:
+        return []
+    if not isinstance(l, ltypes):
+        return [l]
+
+    ltype = type(l)
+    l = list(l)
+    i = 0
+    while i < len(l):
+        while isinstance(l[i], ltypes):
+            if not l[i]:
+                l.pop(i)
+                i -= 1
+                break
+            else:
+                l[i:i + 1] = l[i]
+        i += 1
+    return ltype(l)