Handle exception if rhyme url cannot be found

rilke.py

@@ -1,16 +1,17 @@
 from argparse import ArgumentParser
-from enum import Enum
 from bs4 import BeautifulSoup
+from enum import Enum
+from sys import stderr
+from typing import Iterator, NewType
 import re
 import requests
-from typing import Iterator, NewType
 
+Url = NewType("Url", str)
 class Language(Enum):
     EN = "en"
     DE = "de"
 
 DEFAULT_LANG = Language.DE
-Url = NewType("Url", str)
 
 def cook_soup(url: Url) -> BeautifulSoup:
     return BeautifulSoup(requests.get(url).text, "lxml")
@@ -24,30 +25,30 @@ def entry_url(word: str, lang: Language = DEFAULT_LANG) -> Url:
 def rhymes_url(entry_url: Url, lang: Language = DEFAULT_LANG) -> Url:
     soup = cook_soup(entry_url)
     result_url = base_url(lang)
-    try:
-        if lang == Language.DE:
-            result_url += soup.find("a", href=re.compile(r"/wiki/Reim:Deutsch:.*"))["href"]
-        elif lang == Language.EN:
-            result_url += soup.find("a", href=re.compile(r"/wiki/Rhymes:English/.*"))["href"]
-        return result_url
-    except:
+    if lang == Language.DE:
+        pattern = re.compile(r"/wiki/Reim:Deutsch:.*")
+    elif lang == Language.EN:
+        pattern = re.compile(r"/wiki/Rhymes:English/.*")
+    anchor = soup.find("a", href=pattern)
+    if anchor is not None:
+        return result_url + anchor["href"]
+    else:
         raise ValueError("Entry at {} not found.".format(entry_url))
 
 def find_rhymes(rhymes_url: Url) -> Iterator[str]:
     soup = cook_soup(rhymes_url)
     for li in soup.select("div#content ul > li > a"):
-        try:
-            yield li.text
-        except KeyError:
-            continue
+        yield li.text
 
 if __name__ == "__main__":
     parser = ArgumentParser(description="Find your rhyme in no time")
     parser.add_argument("entry", metavar="WORD", type=str, help="the word to rhyme")
     parser.add_argument("-l", "--lang", help="the language", choices=["de", "en"], nargs="?", default="de")
     args = parser.parse_args()
-
-    entry = entry_url(args.entry, lang=Language(args.lang))
-    rhymes = rhymes_url(entry, lang=Language(args.lang))
-    for rhyme in find_rhymes(rhymes):
-        print(rhyme)
+    try:
+        entry = entry_url(args.entry, lang=Language(args.lang))
+        rhymes = rhymes_url(entry, lang=Language(args.lang))
+        for rhyme in find_rhymes(rhymes):
+            print(rhyme)
+    except ValueError as error:
+        stderr.write("{}\n".format(error))