From d41e6ddf72377ecfc6b175370882e8561544a2c2 Mon Sep 17 00:00:00 2001
From: Daniel Shimon <daniel.shimon22@gmail.com>
Date: Wed, 5 Aug 2020 17:42:19 +0300
Subject: [PATCH] Call repr() when pretty() fails in _pprint_displayhook

---
 news/print-mocks-correctly.rst | 23 +++++++++++++++++++++++
 xonsh/main.py                  |  4 +++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 news/print-mocks-correctly.rst

diff --git a/news/print-mocks-correctly.rst b/news/print-mocks-correctly.rst
new file mode 100644
index 0000000000..2e0943a0fa
--- /dev/null
+++ b/news/print-mocks-correctly.rst
@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Viewing mock objects in the shell
+
+**Security:**
+
+* <news item>
diff --git a/xonsh/main.py b/xonsh/main.py
index 0a3c71d29d..ce3ac3b3c9 100644
--- a/xonsh/main.py
+++ b/xonsh/main.py
@@ -251,9 +251,11 @@ def _pprint_displayhook(value):
         builtins._ = value
         return
     env = builtins.__xonsh__.env
+    printed_val = None
     if env.get("PRETTY_PRINT_RESULTS"):
         printed_val = pretty(value)
-    else:
+    if not isinstance(printed_val, str):
+        # pretty may fail (i.e for unittest.mock.Mock)
         printed_val = repr(value)
     if HAS_PYGMENTS and env.get("COLOR_RESULTS"):
         tokens = list(pygments.lex(printed_val, lexer=pyghooks.XonshLexer()))