Fix default encoding issue

3 files changed, 32 insertions, 2 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0f6b2758..20261be4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ Changelog
 - Fixed relative import sorting bug (Issue #417)
 - Fixed "no_lines_before" to also be respected from previous empty sections.
 - Fixed slow-down introduced by finders mechanism by adding a LRU cache (issue #848)
+- Fixed issue #842 default encoding not-set in Python2
 
 ### 4.3.9 - Feburary 25, 2019 - hot fix release
 - Fixed a bug that led to an incompatibility with black: #831
diff --git a/isort/__main__.py b/isort/__main__.py
index 186c98e8..91cc154d 100644
--- a/isort/__main__.py
+++ b/isort/__main__.py
@@ -1,5 +1,9 @@
 from __future__ import absolute_import
 
-from isort.main import main
+from isort.pie_slice import apply_changes_to_python_environment
+
+apply_changes_to_python_environment()
+
+from isort.main import main  # noqa: E402 isort:skip
 
 main()
diff --git a/isort/pie_slice.py b/isort/pie_slice.py
index 2209cb4e..569ea76e 100644
--- a/isort/pie_slice.py
+++ b/isort/pie_slice.py
@@ -30,14 +30,39 @@ PY2 = sys.version_info[0] == 2
 PY3 = sys.version_info[0] == 3
 VERSION = sys.version_info
 
-__all__ = ['PY2', 'PY3', 'lru_cache']
+__all__ = ['PY2', 'PY3', 'lru_cache', 'apply_changes_to_python_environment']
 
 
 if PY3:
     input = input
+
+    def apply_changes_to_python_environment():
+        pass
 else:
     input = raw_input  # noqa: F821
 
+    python_environment_changes_applied = False
+
+    import sys
+    stdout = sys.stdout
+    stderr = sys.stderr
+
+    def apply_changes_to_python_environment():
+        global python_environment_changes_applied
+        if python_environment_changes_applied or sys.getdefaultencoding() == 'utf-8':
+            python_environment_changes_applied = True
+            return
+
+        try:
+            reload(sys)
+            sys.stdout = stdout
+            sys.stderr = stderr
+            sys.setdefaultencoding('utf-8')
+        except NameError:  # Python 3
+            sys.exit('This should not happen!')
+
+        python_environment_changes_applied = True
+
 
 if sys.version_info < (3, 2):
     try: