Merge pull request #47 from cs50/develop

prevent shadowing of package files

Author: dmalan

setup.py

@@ -16,5 +16,5 @@
     package_dir={"": "src"},
     packages=["cs50"],
     url="https://github.com/cs50/python-cs50",
-    version="2.3.2"
+    version="2.3.3"
 )

src/cs50/__init__.py

@@ -1,13 +1,6 @@
+import os
 import sys
 
-from .cs50 import eprint, get_char, get_float, get_int, get_string
-try:
-    from .cs50 import get_long
-except:
-    pass
-
-from . import flask
-
 
 class CustomImporter(object):
     """
@@ -31,4 +24,28 @@ def load_module(self, name):
         return SQL
 
 
-sys.meta_path.append(CustomImporter())
+try:
+
+    # Save student's sys.path
+    path = sys.path[:]
+
+    # In case student has files that shadow packages
+    sys.path = [p for p in sys.path if p not in ("", os.getcwd())]
+
+    # Import cs50_*
+    from .cs50 import eprint, get_char, get_float, get_int, get_string
+    try:
+        from .cs50 import get_long
+    except Exception:
+        pass
+
+    # Replace Flask's logger
+    from . import flask
+
+    # Lazily load CS50.SQL
+    sys.meta_path.append(CustomImporter())
+
+finally:
+
+    # Restore student's sys.path (just in case library raised an exception that caller caught)
+    sys.path = path