Update solution 020 [Python3]

Author: chakyam

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "python.pythonPath": "/usr/bin/python3"
+}

solution/020.Valid Parentheses/Solution.py

@@ -0,0 +1,24 @@
+class Solution:
+    def isValid(self, s):
+        """
+        :type s: str
+        :rtype: bool
+        """
+        a="()"
+        b="[]"
+        c="{}"
+        f=False
+        if s == '':
+            return True
+        while s != '':
+            s=s.replace(a,'')
+            s=s.replace(b,'')
+            s=s.replace(c,'')
+            if s == '':
+                f=True
+                return f
+            if (a in s) or (b in s) or (c in s):
+                pass
+            else:
+                f=False
+                return f