diff --git a/python/paddle/fluid/core.py b/python/paddle/fluid/core.py
index cf2ae6fd362234ce663ea85a7b79dc47771e76ea..0fbdea2dbcac678fe446f7ae0a2918a13aea29e3 100644
--- a/python/paddle/fluid/core.py
+++ b/python/paddle/fluid/core.py
@@ -235,7 +235,7 @@ def less_than_ver(a, b):
 # The final solution is to upgrade glibc to > 2.22 on the target system.
 if platform.system().lower() == 'linux':
     libc_type, libc_ver = get_libc_ver()
-    if libc_type == 'glibc' and less_than_ver(libc_ver,'2.23'):
+    if libc_type == 'glibc' and less_than_ver(libc_ver, '2.23'):
         try:
             pre_load('libgomp')
         except Exception as e:
diff --git a/python/requirements.txt b/python/requirements.txt
index a83261d5963691d086d00eeec9871eb9c67ca18e..c8d3b2af1794bb0858b187d6a4c641322f50cdd1 100644
--- a/python/requirements.txt
+++ b/python/requirements.txt
@@ -4,10 +4,10 @@ numpy>=1.13, <=1.16.4 ; python_version<"3.5"
 numpy>=1.13 ; python_version>="3.5"
 protobuf>=3.1.0
 gast==0.3.3
-#matplotlib<=2.2.4 ; python_version<"3.6"
+matplotlib<=2.2.4 ; python_version<"3.6"
 scipy>=0.19.0, <=1.2.1 ; python_version<"3.5"
 nltk>=3.2.2, <=3.4 ; python_version<"3.5"
-#matplotlib<=3.2.1 ; python_version>="3.6"
+matplotlib<=3.2.1 ; python_version>="3.6"
 scipy<=1.3.1 ; python_version=="3.5"
 scipy ; python_version>"3.5"
 nltk ; python_version>="3.5"