Adding an Entry in to Dictionary–4.10

There are many ways to add an entry in to dict. There are 4 methods cited in this recipe

import itertools

def addword1(theIndex, word, pagenumber):

theIndex.setdefault(word,\[\]).append(pagenumber)

def addword2(theIndex, word, pagenumber):

if word in theIndex :

    theIndex.setdefault(word,\[\]).append(pagenumber)

else :

    theIndex\[word\] = \[pagenumber\]

def addword3(theIndex, word, pagenumber):

if word in theIndex :

    theIndex.setdefault(word,\[\]).append(pagenumber)

else :

    theIndex\[word\] = \[pagenumber\]

def addword4(theIndex, word, pagenumber):

theIndex\[word\]  = theIndex.get(word,\[\]) +\[pagenumber\]

Out of all the methods, addword1 is the most efficient and addword4 is the least efficient as you are constructing 3 lists for even loop run