Packaging fix: a recent commit made requests and beautifulsoup4 optio…

…nal dependencies, but did not also make them optional imports.

nbsmoke/verify.py

@@ -17,6 +17,18 @@
 
 class VerifyNb(pytest.Item):
     def runtest(self):
+
+        ###################################################
+        # quick hacks to handle missing optional modules
+        _missing = []
+        if BeautifulSoup is None:
+            _missing.append("  * BeautifulSoup not available - please install beautifulsoup4")
+        if requests is None:
+            _missing.append("  * requests not available - please install requests")
+        if _missing:
+            raise Exception("nbsmoke verify failed to execute because of missing modules:\n"+"\n".join(_missing))
+        ###################################################        
+
         filename = self.name
 
         bad_modules = check_modules(filename)
@@ -31,6 +43,17 @@ def runtest(self):
             warnings.warn("%s:\n***** invalid modules: %s\n\n***** bad links: %s\n\n***** bad images: %s\n\n"%(filename,bad_modules,bad_links,bad_images) + "-"*20)
 
 
+try:
+    import requests, requests.exceptions
+except:
+    requests = None
+
+try:
+    from bs4 import BeautifulSoup
+except:
+    # TODO: capture or log the error
+    BeautifulSoup = None
+
 ###################################################
 ###################################################
 # rest of this file is quickly copied in code from datashader
@@ -42,10 +65,6 @@ def runtest(self):
 # https://www.earthsystemcog.org/projects/esmf/regridding is a bad
 # link).
 
-
-import requests, requests.exceptions
-from bs4 import BeautifulSoup
-
 def export_as_html(filename):
     html_exporter = nbconvert.HTMLExporter()
     html_exporter.template_file = 'basic'
@@ -123,3 +142,4 @@ def check_urls(notebook, name, attribute):
             bad_urls.add(url)
 
     return bad_urls
+