Move DD code into its own directory (#6)

reference/ddtrace/utils/importlib.py

@@ -0,0 +1,33 @@
+from __future__ import absolute_import
+
+from importlib import import_module
+
+
+class require_modules(object):
+    """Context manager to check the availability of required modules."""
+
+    def __init__(self, modules):
+        self._missing_modules = []
+        for module in modules:
+            try:
+                import_module(module)
+            except ImportError:
+                self._missing_modules.append(module)
+
+    def __enter__(self):
+        return self._missing_modules
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        return False
+
+
+def func_name(f):
+    """Return a human readable version of the function's name."""
+    if hasattr(f, "__module__"):
+        return "%s.%s" % (f.__module__, getattr(f, "__name__", f.__class__.__name__))
+    return getattr(f, "__name__", f.__class__.__name__)
+
+
+def module_name(instance):
+    """Return the instance module name."""
+    return instance.__class__.__module__.split(".")[0]