Merge pull request #4306 from philjc/issue-4305

news/4305.bugfix.rst

@@ -0,0 +1 @@
+Fix a bug where Pipenv doesn't realize the session is interactive

news/4305.trivial.rst

@@ -0,0 +1 @@
+Print class name instead of the object reference when using installer to install a python version

pipenv/environments.py

@@ -341,11 +341,7 @@ PIPENV_SHELL = (
 )
 
 # Internal, to tell whether the command line session is interactive.
-try:
-    SESSION_IS_INTERACTIVE = _isatty(sys.stdout.fileno())
-except UnsupportedOperation:
-    SESSION_IS_INTERACTIVE = _isatty(sys.stdout)
-
+SESSION_IS_INTERACTIVE = _isatty(sys.stdout)
 
 # Internal, consolidated verbosity representation as an integer. The default
 # level is 0, increased for wordiness and decreased for terseness.

pipenv/installers.py

@@ -71,6 +71,9 @@ class Installer(object):
         self.cmd = self._find_installer()
         super(Installer, self).__init__()
 
+    def __str__(self):
+        return self.__class__.__name__
+
     @abstractmethod
     def _find_installer(self):
         pass