check key is present in python dictionary

Question

Below is the "data" dict

{' node2': {'Status': ' online', 'TU': ' 900', 'Link': ' up', 'Port': ' a0a-180', 'MTU': ' 9000'}, ' node1': {'Status': ' online', 'TU': ' 900', 'Link': ' up', 'Port': ' a0a-180', 'MTU': ' 9000'}}

I am trying key node2 is present or not in data dict in below code but it is not working. Please help

if 'node2' in data:
    print "node2 Present"
else:
    print "node2Not present"

When you say 'it is not working', what result are you getting, exactly? The code you are checking with looks like it should work, so maybe the problem is in the code around it - could you post that here, so we can see what else might be causing a problem? — bouteillebleu, May 18 '17 at 09:26
@akashkarothiya that will result in a ``KeyError`` if the key does not exist! — Mike Scotty, May 18 '17 at 09:29
@mpf82 nope, `get` with return its second argument if the key isn't present in the dictionary. — holdenweb, May 18 '17 at 09:39
@holdenweb The original comment was ``if data[' node2']`` (which would result in a KeyError, as I pointed out). Using ``d.get(key, fallback)`` is fine ofc. @akashkarothiya changed the comment afterwards. — Mike Scotty, May 18 '17 at 09:42

score 1 · Answer 1 · answered May 18 '17 at 10:39

if 'node2' in data:
    print "node2 Present"
else:
    print "node2Not present"

This is a perfectly appropriate way of determining if a key is inside a dictionary, unfortunately 'node2' is not in your dictionary, ' node2' is (note the space):

if ' node2' in data:
    print "node2 Present"
else:
    print "node2Not present"

bharatk · Answer 2 · 2019-07-15T05:07:17.813

0

Check key is present in dictionary :

data = {'node2': {'Status': ' online', 'TU': ' 900', 'Link': ' up', 'Port': ' a0a-180', 'MTU': ' 9000'}, ' node1': {'Status': ' online', 'TU': ' 900', 'Link': ' up', 'Port': ' a0a-180', 'MTU': ' 9000'}}

In python 2.7 version:

has_key()-Test for the presence of key in the dictionary.

if data.has_key('node2'):
    print("found key") 
  else:
    print("invalid key")

In python 3.x version:

key in d - Return True if d has a key, else False.

  if 'node2' in data:
    print("found key") 
  else:
    print("invalid key")

edited Jul 15 '19 at 05:07

answered May 18 '17 at 09:44

bharatk

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You should point out ``has_key`` is removed in Python 3.x (and it's not very pythonic anyway). Source: [Removed. dict.has_key() – use the in operator instead.](https://docs.python.org/3.1/whatsnew/3.0.html#builtins) [I realize the question is flagged "python-2.7", but for the sake of completeness it should be pointed out] - but the "problem" in OP's question is the space in the key. – Mike Scotty May 18 '17 at 09:47

check key is present in python dictionary

2 Answers2