From 871a76ff9f4e437aac5f5c68ed7654543a654fa1 Mon Sep 17 00:00:00 2001
From: Niall Grant <ngfgrant@gmail.com>
Date: Tue, 23 Apr 2019 09:26:35 +0100
Subject: [PATCH] Upgrade to PyYaml 5.1 (#681)

Updates the PyYaml version to 5.1.

Adds in YamlLoader as per https://github.com/yaml/pyyaml/issues/292

Other incompatible changes were reviewed
(https://github.com/yaml/pyyaml/issues/265) and the yaml.Loader appears
to the be only concern for now.

[Resolves #665]
---
 requirements.txt       |  2 +-
 sceptre/cli/helpers.py | 14 ++++++++------
 setup.py               |  2 +-
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/requirements.txt b/requirements.txt
index 3390d6993..421519c63 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,7 @@ packaging==16.8
 pygments==2.2.0
 pytest-runner>=3.0.0,<3.1.0
 pytest>=3.2.0,<3.3.0
-PyYaml>=4.2b1,<5.0
+PyYaml>=5.1,<6.0
 readme-renderer>=24.0
 setuptools>=40.6.2
 six>=1.11.0,<2.0.0
diff --git a/sceptre/cli/helpers.py b/sceptre/cli/helpers.py
index 060618bfc..937ce36ba 100644
--- a/sceptre/cli/helpers.py
+++ b/sceptre/cli/helpers.py
@@ -112,19 +112,21 @@ def _generate_yaml(stream):
             try:
                 if isinstance(item, dict):
                     items.append(
-                            yaml.safe_dump(item, default_flow_style=False, explicit_start=True)
+                        yaml.safe_dump(item, default_flow_style=False, explicit_start=True)
                     )
                 else:
                     items.append(
-                            yaml.safe_dump(
-                                yaml.load(item), default_flow_style=False, explicit_start=True)
+                        yaml.safe_dump(
+                            yaml.load(item, Loader=yaml.FullLoader),
+                            default_flow_style=False, explicit_start=True
+                        )
                     )
             except Exception:
                 print("An error occured whilst writing the YAML object.")
         return yaml.safe_dump(
-                    [yaml.load(item) for item in items],
-                    default_flow_style=False, explicit_start=True
-                )
+            [yaml.load(item, Loader=yaml.FullLoader) for item in items],
+            default_flow_style=False, explicit_start=True
+        )
     else:
         try:
             return yaml.safe_loads(stream)
diff --git a/setup.py b/setup.py
index 9c6bf934b..e8d8e0c06 100755
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,7 @@
 install_requirements = [
     "boto3>=1.3,<2.0",
     "click==7.0",
-    "PyYaml>=4.2b1,<5.0",
+    "PyYaml>=5.1,<6.0",
     "Jinja2>=2.8,<3",
     "packaging==16.8",
     "colorama==0.3.9",