Recursion error Python -

Recursion error Python -

i wrote little bit code seek search word in list. it's not final version , can't yet. however, don't understand wrong code:

def findword (word, t): t.sort() midword = t[len(t)/2] midindex = len(t)/2 if word > midword: del t[:midindex] findword (word, t) elif word < midword: del t[midindex+1:] findword (word, t) elif word == midword: homecoming t else: homecoming none mydic=['apple','banana','peach','pear','melon','lemon','grape','berry'] mydic1 = findword('apple', mydic)

i got runtimeerror: maximum recursion depth exceeded in cmp error when tried search apple , when search other words in list, returns empty list.

please help me figure out wrong. thanks!

take @ code segment:

elif word < midword: del t[midindex+1:] findword (word, t)

in code, come point list reduced 2 elements, is:

t == ['apple', 'banana']

in case, take @ next interactive session:

in [15]: t = ['apple', 'banana'] in [16]: midindex = len(t)/2 in [17]: midindex out[17]: 1 in [18]: t[midindex+1:] out[18]: [] in [19]: del t[midindex+1:] in [20]: t out[20]: ['apple', 'banana']

notice in line 19, deleted nothing, t remains same, called findword same list , run infinite recursion until run out of stack space. should redesign code overcome problem.

another problem see called findword recursively, did not create utilize of homecoming value. instead of:

elif word < midword: del t[midindex+1:] findword (word, t)

you should do:

elif word < midword: del t[midindex+1:] homecoming findword (word, t) additional suggestions do not set t.sort() within findword function. sorting expensive, should once, outside of findword. as others pointed out, bad practice modify list, instead redesign code not that if not homework or exercise, suggest utilize set if want fast look-up python has library module called bisect binary search.

python recursion