functinal programming more compaction style

tinylambda · tinylambda · commit f90d96f859fb · 2020-09-03T00:28:47.000+08:00
diff --git a/functional_program/functional_use_set/functional_xml.py b/functional_program/functional_use_set/functional_xml.py
@@ -1,18 +1,19 @@
 import ssl
 import urllib.request
 import xml.etree.ElementTree as XML
-from typing import Text, List, TextIO, Iterable, Tuple
+from typing import Text, List, TextIO, Iterable, Tuple, TypeVar, Iterator
 
 ssl._create_default_https_context = ssl._create_unverified_context
 
 
 def row_iter_kml(file_obj: TextIO) -> Iterable[List]:
     ns_map = {
         'ns0': 'http://www.opengis.net/kml/2.2',
-        'ns1': 'http://www.google.com/kml/ext/2.2'
+        'ns1': 'http://www.google.com/kml/ext/2.2',
+        'ns2': 'http://earth.google.com/kml/2.1',
     }
-    path_to_points = ('./ns0:Document/ns0:Placemark/'
-                      'ns0:Point/ns0:coordinates')
+    path_to_points = ('./ns2:Document/ns2:Placemark/'
+                      'ns2:Point/ns2:coordinates')
     doc = XML.parse(file_obj)
     return (comma_split(Text(coordinates.text))
             for coordinates in
@@ -35,7 +36,29 @@ def lat_lon_kml(row_iter: Rows) -> Iterable[LL_Text]:
     return (pick_lat_lon(*row) for row in row_iter)
 
 
-url = 'https://raw.githubusercontent.com/googlearchive/kml-samples/gh-pages/kml/Placemark/Point/altitude.kml'
+T_ = TypeVar('T_')
+Pairs_iter = Iterator[Tuple[T_, T_]]
+
+
+def legs(lat_lon_iter: Iterator[T_]) -> Pairs_iter:
+    begin = next(lat_lon_iter)
+    for end in lat_lon_iter:
+        yield begin, end
+        begin = end
+
+
+Text_Iter = Iterable[Tuple[Text, Text]]
+LL_Iter = Iterator[Tuple[float, float]]
+
+
+def float_from_pair(lat_lon_iter: Text_Iter) -> LL_Iter:
+    return (
+        (float(lat), float(lon))
+        for lat, lon in lat_lon_iter
+    )
+
+
+url = 'https://raw.githubusercontent.com/googlearchive/kml-samples/gh-pages/kml_handbook/mvdoqq.kml'
 with urllib.request.urlopen(url) as source:
     v1 = tuple(row_iter_kml(source))
 print(v1)
@@ -45,3 +68,20 @@ def lat_lon_kml(row_iter: Rows) -> Iterable[LL_Text]:
     v2 = tuple(lat_lon_kml(row_iter_kml(source)))
 print(v2)
 
+
+with urllib.request.urlopen(url) as source:
+    flt = ((float(lat), float(lon)) for lat, lon in lat_lon_kml(row_iter_kml(source)))
+    for item in legs(flt):
+        print(item)
+
+print(tuple(flt))
+
+
+with urllib.request.urlopen(url) as source:
+    v3 = legs(float_from_pair(
+        lat_lon_kml(
+            row_iter_kml(source)
+        )))
+print(tuple(v3))
+
+
