Updated code examples to Python 3 (#20765)

guide/english/python/exception-and-error-handling/index.md

@@ -10,24 +10,26 @@ To solve this problem in python we can use `try` and `except`
 
 Example:
 
-```shell
->>> try:
->>> . . . print "this is not a string "+1
->>> except:
->>> . . . print "error"
-error
-```
-and if you want to get error messages in more detail from your code, you can add arguments `except Exception as err`
+```python
+try:
+    print("this is not a string " + 1)
+except:
+    print("error")
 
-```shell
->>> try:
->>> . . . print "this is not a string "+1
->>> except Exception as err:
->>> . . . print "error:\n"+str(err)
-error:
-cannot concatenate 'str' and 'int' objects
+>>> error
+```
+And if you want to get error messages in more detail from your code, you can add arguments `except Exception as err`
+
+```python
+try:
+    print("this is not a string " + 1)
+except Exception as err:
+    print("error:\n" + str(err))
+    
+>>> error:
+>>> must be str, not int
 ```
 
 More Information:
 
-Errors and Exceptions <a href='https://docs.python.org/2/tutorial/errors.html' target='_blank' rel='nofollow'>documentation</a>.
+Errors and Exceptions <a href='https://docs.python.org/3.6/tutorial/errors.html' target='_blank' rel='nofollow'>documentation</a>.