Make load.py more idiomatic.

Also snuck an idiom into db/__init__.py.

diff --git a/pokedex/db/__init__.py b/pokedex/db/__init__.py
index e2790da..aa540a2 100644 (file)
--- a/pokedex/db/__init__.py
+++ b/pokedex/db/__init__.py
@@ -21,7 +21,7 @@ def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
         uri = get_default_db_uri()
 
     ### Do some fixery for MySQL
-    if uri[0:5] == 'mysql':
+    if uri.startswith('mysql:'):
         # MySQL uses latin1 for connections by default even if the server is
         # otherwise oozing with utf8; charset fixes this
         if 'charset' not in uri:

diff --git a/pokedex/db/load.py b/pokedex/db/load.py
index 88f5332..5740f42 100644 (file)
--- a/pokedex/db/load.py
+++ b/pokedex/db/load.py
@@ -53,7 +53,7 @@ def _get_verbose_prints(verbose):
     def print_start(thing):
         # Truncate to 66 characters, leaving 10 characters for a success
         # or failure message
-        truncated_thing = thing[0:66]
+        truncated_thing = thing[:66]
 
         # Also, space-pad to keep the cursor in a known column
         num_spaces = 66 - len(truncated_thing)
@@ -212,12 +212,12 @@ def load(session, tables=[], directory=None, drop_tables=False, verbose=False, s
         # them to the session last
         # ASSUMPTION: Self-referential tables have a single PK called "id"
         deferred_rows = []  # ( row referring to id, [foreign ids we need] )
-        seen_ids = {}       # primary key we've seen => 1
+        seen_ids = set()    # primary keys we've seen
 
         # Fetch foreign key columns that point at this table, if any
         self_ref_columns = []
         for column in table_obj.c:
-            if any(_.references(table_obj) for _ in column.foreign_keys):
+            if any(x.references(table_obj) for x in column.foreign_keys):
                 self_ref_columns.append(column)
 
         new_rows = []
@@ -256,18 +256,18 @@ def load(session, tables=[], directory=None, drop_tables=False, verbose=False, s
             # May need to stash this row and add it later if it refers to a
             # later row in this table
             if self_ref_columns:
-                foreign_ids = [row_data[_.name] for _ in self_ref_columns]
-                foreign_ids = [_ for _ in foreign_ids if _]  # remove NULL ids
+                foreign_ids = set(row_data[x.name] for x in self_ref_columns)
+                foreign_ids.discard(None)  # remove NULL ids
 
                 if not foreign_ids:
                     # NULL key.  Remember this row and add as usual.
-                    seen_ids[row_data['id']] = 1
+                    seen_ids.add(row_data['id'])
 
-                elif all(_ in seen_ids for _ in foreign_ids):
+                elif foreign_ids.issubset(seen_ids):
                     # Non-NULL key we've already seen.  Remember it and commit
                     # so we know the old row exists when we add the new one
                     insert_and_commit()
-                    seen_ids[row_data['id']] = 1
+                    seen_ids.add(row_data['id'])
 
                 else:
                     # Non-NULL future id.  Save this and insert it later!
@@ -286,7 +286,7 @@ def load(session, tables=[], directory=None, drop_tables=False, verbose=False, s
 
         # Attempt to add any spare rows we've collected
         for row_data, foreign_ids in deferred_rows:
-            if not all(_ in seen_ids for _ in foreign_ids):
+            if not foreign_ids.issubset(seen_ids):
                 # Could happen if row A refers to B which refers to C.
                 # This is ridiculous and doesn't happen in my data so far
                 raise ValueError("Too many levels of self-reference!  "