coding style - The most Pythonic way of checking if a value in a dictionary is defined/has zero length -

say have dictionary, , want check if key mapped nonempty value. 1 way of doing len function:

mydict = {"key" : "value", "emptykey" : ""} print "true" if len(mydict["key"]) > 0 else "false"  # prints true print "true" if len(mydict["emptykey"]) > 0 else "false"  # prints false 

however, 1 can rely on semantics of python , how if object defined evaluates true , leave out len call:

mydict = {"key" : "value", "emptykey" : ""} print "true" if mydict["key"] else "false"  # prints true print "true" if mydict["emptykey"] else "false"  # prints false 

however, i'm not sure more pythonic. first feels "explicit better implicit", second feels "simple better complex".

i wonder if leaving out len call bite me dict i'm working doesn't contain strings, contain other len-able types (lists, sets, etc). otoh, in former (with len call) if none gets stored value code blow up, whereas non-len version work expected (will eval false).

which version safer , more pythonic?

edit: clarifying assumptions: know key in dictionary, , know values len-able. cannot avoid having zero-length values enter dictionary.

edit #2: seems people missing point of question. i'm not trying determine pythonic/safest way of checking if key present in dictionary, i'm trying check if a value has 0 length or not

if know key in dictionary, use

if mydict["key"]:     ... 

it simple, easy read, , says, "if value tied 'key' evaluates true, something". important tidbit know container types (dict, list, tuple, str, etc) evaluate true if len greater 0.

it raise keyerror if premise key in mydict violated.

all makes pythonic.