Use type hints

- Also, silence mypy.

shakyground2/import_fdsnws_eq.py

@@ -20,24 +20,33 @@ Can run standalone:
 import datetime
 import os
 import sys
+from typing import List, Optional, Union
 import urllib.request as ul
 from xml.etree import ElementTree as ET
 import yaml
 
 
-FDSNWS_ENDPOINT = "http://geofon.gfz-potsdam.de/fdsnws/event/1/"
-QUAKEML_NS = {"ns": "http://quakeml.org/xmlns/bed/1.2"}
+FDSNWS_ENDPOINT: str = "http://geofon.gfz-potsdam.de/fdsnws/event/1/"
+QUAKEML_NS: dict = {"ns": "http://quakeml.org/xmlns/bed/1.2"}
 
 
-def fetch_fm(root, ns, preferredfmID):
+def _perror(msg: str) -> None:
+    print(msg, file=sys.stderr)
+
+
+def fetch_fm(root: ET.Element, ns: dict, preferredfmID: str) -> list:
     """
     Extract interesting properties from the focal mechanism with
     the given publicID.
 
     root: ElementTree root element.
-    ns (string): string, its namespace.
+    ns (dict): its namespace.
     preferredfmID (string): the focal mechanism to hunt for.
 
+    Returns a list of one dictionary filled from each of the
+    <nodalPlane1> and <nodalPlane2> components of the <nodalPlane>
+    element.
+
     """
     for fm in root[0][0].findall("ns:focalMechanism", ns):
         if fm.attrib["publicID"] != preferredfmID:
@@ -47,23 +56,33 @@ def fetch_fm(root, ns, preferredfmID):
 
         np = fm.find("ns:nodalPlanes", ns)
         # Expect there's only one <nodalPlanes>!
+        if not np:
+            _perror("Oops: no <nodalPlanes> object seen")
+            break
 
-        d = [None, None]
+        d: List[dict] = []
         for k in range(2):
             plane = np.find("ns:nodalPlane" + str(k + 1), ns)
             d[k] = dict()
+            if not plane:
+                continue
             for child in plane:
-                v = child.find("ns:value", ns).text
+                found = child.find("ns:value", ns)
+                if not found:
+                    continue
+                v = found.text
                 tag = child.tag
                 tag = tag[tag.index("}") + 1 :]
                 try:
-                    d[k][tag] = float(v)
+                    d[k][tag] = float(str(v))
                 except ValueError:
                     pass
     return d
 
 
-def fetch_magnitude(root, ns, preferredmagnitudeID):
+def fetch_magnitude(
+    root: ET.Element, ns: dict, preferredmagnitudeID: str
+) -> Union[float, None]:
     for m in root[0][0].findall("ns:magnitude", ns):
         if m.attrib["publicID"] != preferredmagnitudeID:
             continue
@@ -71,20 +90,23 @@ def fetch_magnitude(root, ns, preferredmagnitudeID):
     child = m.find("ns:mag", ns)
     if not child:
         return None
-    v = child.find("ns:value", ns).text
+    value = child.find("ns:value", ns)
+    if not value:
+        return None
+    v = value.text
     try:
-        mag = float(v)
+        mag = float(str(v))
     except ValueError:
-        mag = None
+        return None
     return mag
 
 
-def fetch_origin(root, ns, preferredoriginID):
+def fetch_origin(root, ns: dict, preferredoriginID: str) -> dict:
     """
     Extract interesting properties from the origin with given publicID.
 
     root: ElementTree root element.
-    ns (string): the XML object's namespace.
+    ns (dict): the XML object's namespace.
     preferredoriginID (string): the origin to hunt for.
     """
     for o in root[0][0].findall("ns:origin", ns):
@@ -111,7 +133,7 @@ def fetch_origin(root, ns, preferredoriginID):
     return d
 
 
-def fetch_quakeml_ws(evid):
+def fetch_quakeml_ws(evid: str) -> str:
     """
     Query fdsnws-event web service, and return string
     to fetch_quakeml() for parsing.
@@ -142,7 +164,7 @@ def fetch_quakeml_ws(evid):
     return buf
 
 
-def fetch_quakeml(path):
+def fetch_quakeml(path: str) -> Union[dict, None]:
     """
     Prepare a dictionary holding the interesting things found by
     reading the QuakeML file served for a given event.
@@ -176,15 +198,32 @@ def fetch_quakeml(path):
         # e.g. "smi:org.gfz-potsdam.de/geofon/gfz2021ekhv"
         evid = event.attrib["publicID"].split("/")[-1]
     except AttributeError:
-        print("Oops")
+        _perror("Oops, couldn't get event id from " + event.attrib["publicID"])
 
-    preferredoriginID = root[0][0].find("ns:preferredOriginID", ns).text
-    preferredmagID = root[0][0].find("ns:preferredMagnitudeID", ns).text
+    preferredoriginIDElem = root[0][0].find("ns:preferredOriginID", ns)
+    if not preferredoriginIDElem:
+        return None
+    preferredoriginID = preferredoriginIDElem.text
+
+    preferredmagID = None
+    preferredMagnitudeIDElem = root[0][0].find("ns:preferredMagnitudeID", ns)
+    if preferredMagnitudeIDElem:
+        try:
+            preferredmagID = preferredMagnitudeIDElem.text
+        except AttributeError:
+            pass
+
+    preferredfmID = None
     try:
-        preferredfmID = root[0][0].find("ns:preferredFocalMechanismID", ns).text
+        preferredfmIDElem = root[0][0].find("ns:preferredFocalMechanismID", ns)
+        if preferredfmIDElem:
+            preferredfmID = preferredfmIDElem.text
     except AttributeError:
-        preferredfmID = None
+        pass
 
+    if not preferredoriginID:
+        print("Oops, no preferredOriginID was found")
+        return None
     origin = fetch_origin(root, ns, preferredoriginID)
 
     (d, t) = origin.pop("time").split("T", 2)
@@ -195,14 +234,16 @@ def fetch_quakeml(path):
     # d = datetime.date(2020, 1, 1)
     # t = datetime.time(12, 0, 30, 123000)
 
+    focalmech = None
     if preferredfmID:
         focalmech = fetch_fm(root, ns, preferredfmID)
-    else:
-        focalmech = None
 
     # Should this be event's preferred magnitude,
     # or the preferred focal mechanism's <momentMagnitudeID>?
     # Probably they are the same thing...
+    if not preferredmagID:
+        print("Oops, no preferredMagnitudeID was found")
+        return None
     mag = fetch_magnitude(root, ns, preferredmagID)
 
     return {