use ujson if available, and optimize bbox function

new version of coordstring_bbox function is approx 2x as fast with a
string of 1000 random 2D coordinates

Note: removes NumpyAwareJSONEncoder, meaning that numpy >= 1.9 is
required if inputs have coordinates stored in numpy arrays

picogeojson/bbox.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 
 def geom_bbox(geom):
     if type(geom).__name__ == "Point":
@@ -45,10 +46,16 @@ def feature_collection_bbox(coll):
     return bbx
 
 def coordstring_bbox(coordinates):
+    """ Given a string of coodinates, return the bounds as a *2×N* length list,
+    where *N* is the number of dimensions (at least two).
+
+    The bounding list is structured `xmin, ymin[, ...], xmax, ymax[, ...]`.
+    """
     ndim = len(coordinates[0])
     bbx = [0 for _ in range(2*ndim)]
-    for dim in range(ndim):
-        bbx[dim] = min(crds[dim] for crds in coordinates)
-        bbx[dim+ndim] = max(crds[dim] for crds in coordinates)
+    components = [[a[i] for a in coordinates] for i in range(ndim)]
+    for i, comp in enumerate(components):
+        bbx[i] = min(comp)
+        bbx[i+ndim] = max(comp)
     return bbx
 

picogeojson/geojson.py

@@ -13,7 +13,11 @@
 - `Serializer` validates and converts named tuples to GeoJSON strings.
 """
 
-import json
+try:
+    import ujson as json
+except ImportError:
+    import json
+
 from .types import (Point, LineString, Polygon,
                     MultiPoint, MultiLineString, MultiPolygon,
                     GeometryCollection, Feature, FeatureCollection)
@@ -25,23 +29,6 @@
 DEFAULTCRS = {"type": "name",
               "properties": {"name": "urn:ogc:def:crs:OGC:1.3:CRS84"}}
 
-class NumpyAwareJSONEncoder(json.JSONEncoder):
-    """ Numpy-specific numbers prior to 1.9 don't inherit from Python numeric
-    ABCs. This class is a hack to coerce numpy values into Python types for
-    JSON serialization. """
-
-    def default(self, o):
-        if not hasattr(o, "dtype") or (hasattr(o, "__len__") and (len(o) != 1)):
-            return json.JSONEncoder.default(self, o)
-        elif o.dtype in ("int8", "int16", "int32", "int64"):
-            return int(o)
-        elif o.dtype in ("float16", "float32", "float64", "float128"):
-            return float(o)
-        elif o.dtype in ("complex64", "complex128", "complex256"):
-            return complex(o)
-        else:
-            raise TypeError("not a recognized type")
-
 class Deserializer(object):
 
     def __init__(self, defaultcrs=DEFAULTCRS):
@@ -165,9 +152,8 @@ def __init__(self, antimeridian_cutting=True, enforce_poly_winding=True, write_b
         self.write_bbox = write_bbox
         return
 
-    def __call__(self, geom, indent=None):
-        return json.dumps(self.geojson_asdict(geom), indent=indent,
-                          cls=NumpyAwareJSONEncoder)
+    def __call__(self, geom, indent=0):
+        return json.dumps(self.geojson_asdict(geom), indent=indent)
 
     def geojson_asdict(self, geom, parent_crs=None):
         if isinstance(geom, Feature):