Python 2.7.8：打印子字典值？

Question

I'm using ConfigParser which returns a dictionary of configuration data as such:

{'general': {'UserKey': 'thisisatestkey'}}

If I want to simply print the value of the UserKey key (in this case thisisatestkey), then I generally just do a print "Your key is: {0}".format(mydictvar.get('UserKey')) .

If I just print out the raw dict to a string I get the above. If I use the print statement above I get result of None since there is no key in the root of the dict called UserKey. If I .get('general') I just get: {'UserKey': 'thisisatestkey'}

Obviously I could do a fore loop like so:

keydic = cp.get_config_data()

for m, k in keydic.iteritems():
    for s, v in k.iteritems():
        userkey = v

and then print userkey which works fine. But I want to know how I can just avoid having to do the entire for loop first and just print the darned value right inline? Thanks!

Answer 1

You can use

mydictvar['general']['UserKey']

Or, if keys might be missing

mydictvar.get('general', {}).get('UserKey')

mydictvar['general'] returns a dictionary object; you can then just apply [...] to that value to retrieve the next key.

This works in string formatting too:

>>> mydictvar = {'general': {'UserKey': 'thisisatestkey'}}
>>> print "Your key is: {0[general][UserKey]}".format(mydictvar)
Your key is: thisisatestkey

Answer 2

simply without loop:

>>> my_dict = {'general': {'UserKey': 'thisisatestkey'}}
>>> my_dict['general']['UserKey']
'thisisatestkey'