Python上的列表索引错误

Question

Im writing a program to try to calculate how many times the most repeated word in a list occurs. I keep getting an error that says: index error. Even though when I print the list of my word_list, it shows there are 108 elements. Could someone point me in the right direction as to where my error is?

  length = len(word_list)
  num = 0
  print(length)

    while num <= length:

            ele = word_list[num]

            if ele in wordDict:
                    wordDict[ele] = wordDict[ele] +1
                    repeat = repeat + 1
                    if repeat > highestRepeat:
                            highestRepeat = repeat

            else:
                    wordDict[ele] = 1
                    repeat = 1

            num = num+1

Answer 1

List indexing goes from 0 to length-1 .

In your while loop, you've told the num to go from 0 to length . That's why you have an index error.

Simply change num <= length to num < length . That should fix your code for you.

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As an aside, there are much better ways to do this particular task. A simple two liner:

from collections import Counter

print(Counter(word_list).most_common(1))

Counter will calculate the frequencies of each element in your list for you, and most_common(1) will return the element with the highest frequency in your list.

Answer 2

Just to mention that there is a more compact solution to your problem:

word_list =['this' ,'is', 'a', 'test', 'is']

for word in set(word_list):
    print word, ": ", word_list.count(word)